AMS2500 Performance Report

Hitachi AMS 2500 Using 200GB SSD Drives – Scalability Analysis

A Performance Brief

By Alan Benway (Performance Measurement Group, Technical Operations)

Confidential – Hitachi Data Systems Internal and Channel Partner Use Only

August 2010

Hitachi Data Systems Internal and Channel Partner Confidential

Executive Summary The purpose of this testing was to establish a variety of performance comparisons of SSD and SAS drives on the Hitachi Adaptable Modular Storage 2500 (AMS 2500) midrange storage array. Various tests used 5, 10, 15 and 20 200GB SSD or SAS disks, each used in a RAID-5 (4D+1P) group. No other raid type was tested, since our field experience shows that almost all users use SSDs in Raid 5 configurations in order to maximize their price/performance ratio. In some tests (random write, for instance), we know that more IOPs would probably result if we ran R10 configurations. Additionally, some SSD tests were also run with the use of Hitachi Dynamic Provisioning for comparison. The AMS 2500’s Hardware Load Balancing feature was “Enabled.” There were no copy products license keys enabled, so the maximum amount of cache was available. There were 11 categories of tests conducted in all.

The performance results are presented in the charts in the Test Results Summary section of this report. While we attempt to profile a variety of application characteristics, no benchmark can replicate a real world application as well as the actual applications themselves.

Shown below are result summaries from Test 1 (random) and Test 2 (sequential). These tables show the measured SSD results and the interpolated 146GB 15K RPM SAS results from an AMS 2500 that show the number of SAS drives required to match the SSD result. Note that the number of host paths in use varied by the number of LUNs tested. Up to four host paths were used for the SSD tests, and up to 16 were used for the SAS tests. For example, in the SAS tests, 14 LUNs would have been mapped over 14 paths, while 72 LUNs would have been mapped across 16 paths.

As a general rule of thumb, 30 SSDs on the AMS 2500 can replace 360 15K RPM SAS drives for meeting random performance requirements. When reviewing past SAS test results, one can see that the system scalability limit for certain RAID levels and workloads can occur well below 360 SAS disks. As such, one cannot expect to use 30 SSD drives plus 120 SAS disks with heavy concurrent loads that have significant write components. In the SAS sequential results below, when using RAID-5 (4D+1P) the system limit was at about 160 disks. As such, it is expected that heavy sequential use of 30 SSDs in RAID-5 (4D+1P) would consume all of the arrays internal resources.

100% Random Read Comparison

100% Random Read SSD 1‐4 Paths

8 threads/LUN 4KB RAID‐5 4+1

Drives LUNs Threads IOPS RT [msec] IOPS/SSD

5 1 8 15,148 0.5 3030

10 2 16 30,437 0.5 3043

15 3 24 45,298 0.5 3020

20 4 32 60,086 0.5 3004

100% Random Read SAS 15k 16 Paths

8 threads/LUN 4KB RAID‐5 4+1

Drives LUNs Threads IOPS RT [msec] IOPS/HDD

90 18 144 15,200 9.5 169

180 36 288 30,400 9.5 169

270 54 432 45,600 9.5 169

360 72 576 60,800 9.5 169

480* 96 96 79,500 9.7 166


100% Random Write Comparison

Random Write SSD 1‐4 Paths

1 thread/LUN 4KB RAID‐5 4+1

Drives LUNs Threads IOPS RT [msec] IOPS/SSD

5 1 1 4,498 0.2 900

10 2 2 10,198 0.2 1,020

15 3 3 12,767 0.2 851

20 4 4 16,687 0.2 834

Random Write SAS 15k 14‐16 Paths

1 thread/LUN 4KB RAID‐5 4+1

Drives LUNs Threads IOPS RT [msec] IOPS/HDD

70 14 14 4,700 22.0 67

160 32 32 9,600 27.0 60

480* 96 96 15,000 48.0 33

‐ ‐ ‐ ‐ ‐ ‐

*System performance limit.

100% Sequential Read Comparison

100% Sequential Read SSD 1‐4 Paths

1 thread/LUN 256kb RAID‐5 4+1

Drives LUNs Threads MB/s MB/s SSD

5 1 1 321.2 64.2

10 2 2 623.5 62.4

15 3 3 910.7 60.7

20 4 4 1224.6 61.2

100% Sequential Read SAS 15k 1‐16 Paths


Drives LUNs Threads MB/s MB/s HDD

5 1 1 295 59

10 2 2 590 59

45 9 9 900 20

60 12 12 1,200 20

160* 52 52 2300 14.5


100% Sequential Write Comparison

100% Sequential Write SSD 1‐4 Paths


Drives LUNs Threads MB/s MB/s SSD

5 1 1 257.9 51.6

10 2 2 506.6 50.7

15 3 3 716.7 47.8

20 4 4 931.7 46.6

100% Sequential Write SAS 15k 2‐16 Paths


Drives LUNs Threads MB/s MB/s HDD

10 2 2 454.9 45.5

55 11 11 495 9

80 16 16 718 9

130 26 26 910 7

160* 52 52 1095 6.8

*System performance limit.


Notices and Disclaimer Copyright © 2010 Hitachi Data Systems Corporation. All rights reserved.

The performance data contained herein was obtained in a controlled isolated environment. Actual results that may be obtained in other operating environments may vary significantly. While Hitachi Data Systems Corporation has reviewed each item for accuracy in a specific situation, there is no guarantee that the same results can be obtained elsewhere.

All designs, specifications, statements, information and recommendations (collectively, "designs") in this manual are presented "AS IS," with all faults. Hitachi Data Systems Corporation and its suppliers disclaim all warranties, including without limitation, the warranty of merchantability, fitness for a particular purpose and non-infringement or arising from a course of dealing, usage or trade practice. In no event shall Hitachi Data Systems Corporation or its suppliers be liable for any indirect, special, consequential or incidental damages, including without limitation, lost profit or loss or damage to data arising out of the use or inability to use the designs, even if Hitachi Data Systems Corporation or its suppliers have been advised of the possibility of such damages.

Adaptable Modular Storage® is a registered trademark of Hitachi Data Systems, Inc. in the United States, other countries, or both.

Other company, product or service names may be trademarks or service marks of others.

This document has been reviewed for accuracy as of the date of initial publication. Hitachi Data Systems Corporation may make improvements and/or changes in product and/or programs at any time without notice.

No part of this document may be reproduced or transmitted without written approval from Hitachi Data Systems Corporation.

WARNING: This document can only be used as HDS internal documentation for informational purposes only. This documentation is not meant to be disclosed to customers or discussed without a proper non-disclosure agreement (NDA).


Document Revision Level

Revision Date Description

1.0 July 2010 Initial Release

1.1 Aug 2010 Fixed typo in executive summary table (seq writes, SAS)

Reference Hitachi AMS 2000 Architecture and Concepts Guide

Hitachi AMS 2500 Dynamic Provisioning Concepts, Performance, and Best Practices Guide

Contributors The information included in this document represents the expertise, feedback, and suggestions of a number of skilled practitioners. The author would like to recognize and thank the following contributors or reviewers of this document:

Yusuke Nishihara, Engineer, Disk Array Software Development Dept. III, Storage Systems Development, Disk Array Systems Division, Hitachi LTD

Ian Vogelesang, Performance Measurement Group - Technical Operations

Mel Tungate, Product Management, Midrange

Table of Contents

Executive Summary ............................................................................................................................................................. 2

Purpose of This Testing ....................................................................................................................................................... 9

Workload Generator Information ........................................................................................................................................ 9

Test Configurations and Workloads ................................................................................................................................... 9

Configuration .................................................................................................................................................. 9

Test Methodologies ...................................................................................................................................... 10

Tests 1 and 2: Uniform Workloads, RAID Group and Block Size Scalability, Random and Sequential, SSD and SAS ........................................................................................................................................................................ 11

Tests 3 and 4: Mixed Workloads, RAID Group and Block Size Scalability, Random and Sequential, SSD and SAS11

Test 5: Single Workload, Single RAID Group, Thread Scalability, SSD and SAS .................................................. 12

Tests 6 to 9: Mixed Workloads, RAID Group and Block Size Scalability, Random and Sequential, SSD, HDP and non-HDP ................................................................................................................................................................ 12

Tests 10 and 11: Mixed Workloads, 4 RAID Groups, Random, SSD and SAS, HDP and non-HDP ...................... 12

AMS 2500 Test Results Summary ..................................................................................................................................... 13

Test 1 Results .............................................................................................................................................. 13

Random Read Summary ........................................................................................................................................ 13

Random Write Summary ........................................................................................................................................ 14

Test 2 Results .............................................................................................................................................. 14

Sequential Read Summary .................................................................................................................................... 14

Sequential Write Summary ..................................................................................................................................... 15

Test 3 Results .............................................................................................................................................. 16

Observations .......................................................................................................................................................... 16

Test 4 Results .............................................................................................................................................. 17

Observations .......................................................................................................................................................... 17

Test 5 Results .............................................................................................................................................. 21

Test 6 Results (non-HDP) ............................................................................................................................ 22

Test 7 Results (HDP) ................................................................................................................................... 22

Test 8 Results (non-HDP) ............................................................................................................................ 23

Test 9 Results (HDP) ................................................................................................................................... 23

Test 10 Results ............................................................................................................................................ 23

Test 11 Results (HDP) ................................................................................................................................. 25

Conclusions ........................................................................................................................................................................ 26

APPENDIX A. Test Configuration Details ......................................................................................................................... 28

Test information ........................................................................................................................................... 28

Host Configuration ....................................................................................................................................... 28

Storage Configuration .................................................................................................................................. 28

APPENDIX B. Test-1 Full Results ...................................................................................................................................... 29

APPENDIX C. Test-2 Full Results ...................................................................................................................................... 33

APPENDIX D. Test-3 Full Results ...................................................................................................................................... 37

Random Mixed Workloads ..................................................................................................................................... 37

APPENDIX E. Test-4 Full Results ...................................................................................................................................... 39

Sequential Workloads Using Default 256KB RAID Chunk ..................................................................................... 39

Sequential Workloads Using Optional 64KB RAID Chunk ..................................................................................... 41


Hitachi AMS 2500 Using 200GB SSD HDDs – Scalability Analysis

A Performance Brief

By Alan Benway (Performance Measurement Group, Technical Operations)

Purpose of This Testing The purpose of this testing was to establish a variety of performance comparisons of SSD and SAS drives on the Hitachi Adaptable Modular Storage 2500 (AMS 2500) midrange storage array. Various tests used 5, 10, 15 and 20 200GB SSD or 146GB 15k SAS disks in a RAID-5 (4D+1P) configuration. Additionally, some SSD tests were also run with the use of Hitachi Dynamic Provisioning for comparison. The AMS 2500’s Hardware Load Balancing feature was “Enabled.” There were no copy products license keys enabled, so the maximum amount of cache was available.

These results will help answer questions about the kind of performance capabilities to expect with various workloads when using a 0% cache hit ratio. The performance results are presented in the charts in the Test Results Summary section of this report. While we attempt to profile a variety of application characteristics, no benchmark can replicate a real world application as well as the actual applications themselves.

Workload Generator Information Vdbench and IOmeter were used to generate a variety of I/O workloads against raw volumes (no file systems, with their various overheads). Various workload parameters such as I/O rates, file sizes, transfer sizes, thread counts, read/write ratios, and random versus sequential were controlled by parameter files. By using raw volumes, the tests bypassed the host file system and its cache, thus more accurately reflecting the I/O performance capabilities of the storage unit.

Test Configurations and Workloads Configuration There was a single Hitachi AMS 2500 midrange storage system used for these tests. The AMS 2500 was configured with 16GB of Cache. A RAID-5 (4D+1P) configuration was used for both SSD and SAS configurations. Various LUN sizes were used during these tests, with an 8GB, 133GB, or 362GB LUN configured. On some test there were two LUNs per RAID Group rather than one.

There was one HP DL585 G2 server used, with 4 x 3GHz Opteron dual-core processors, 16GB of RAM, and four Qlogic QLE2462 PCIe 4Gb/sec Fibre Channel HBAs, with up to 8 4Gb/sec paths used for the tests. The operating system used was Microsoft Windows Server 2003 with Service Pack 2.

Table 1 shows the general locations of the SAS and SSD drives for each RAID Group. Four disk trays were used, with five empty drive slots per tray. From one to four host ports (1 or 2 per controller) were used for these tests.


Table 1. AMS 2500 RAID Group Layout – RAID-5 (4D+1P)

Tray‐3 RG 3 SAS RG 3 SSD




Slot # 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Test Methodologies There were eleven types of tests performed on SSD drives, with six of these tests also run on SAS disks. The details of these tests are shown below in Tables 1 and 2. Note that tests 6, 8 and 11 also used HDP. While SAS results are shown later on below, one need examine previous AMS 2500 SAS scalability test results to see how many SAS disks are needed to achieve comparable levels with these SSD results. Also note that these tests do not explore the use of 20 SSD drives along with a scaled number of SAS disks to see where the internal bandwidth of the controllers is exhausted.

Table 2. Test Configuration Overview

Test Test Name Configuration

Set # HDD/SSD RAID‐5 4D+1P Groups LUN / RG LU Size HDP

1 Basic Performance HDD, SSD 1, 2, 3, 4 1 8GB ‐

2 HDD, SSD 1, 2, 3, 4 1 8GB ‐

3 HDD, SSD 1, 2, 3, 4 1 8GB ‐

4 HDD, SSD 1, 2, 3, 4 1 8GB ‐

5 HDD, SSD 1 1 362GB ‐

6 HDP Performance SSD 4 (4RG/1pool) 2 133GB yes

7 SSD 4 2 133GB no

8 SSD 4 (4RG/1pool) 2 133GB yes

9 SSD 4 2 133GB no

10 Response Time HDD, SSD 4 2 133GB no

11 Performance SSD 4 2 133GB yes

Table 3. Workload Details by Test

Test Workload Tool

Set # Threads / LU Block Size (KB) Read %

1 R:8,32 / W:1,8 Random .5, 4, 16, 64, 256, 1024 0, 100% IOmeter

2 R:1,8 / W:1,8 Sequential .5, 4, 16, 64, 256, 1024 0, 100% IOmeter

3 8 Random 2, 4, 8, 16 0, 25, 50, 75, 100% Vdbench

4 1 Sequential 64, 128, 256, 512, 1024 0, 25, 50, 75, 100% Vdbench

5 1‐256 Random 8 75% Vdbench

6 4 Random 8 0, 25, 50, 75, 100% Vdbench

7 4 Random 8 0, 25, 50, 75, 100% Vdbench


8 4 Sequential 1024 0, 25, 50, 75, 100% Vdbench

9 4 Sequential 1024 0, 25, 50, 75, 100% Vdbench

10 8 (16,32,64,128) Random 4 0, 70,100% Vdbench

11 8 (16,32,64,128) Random 4 0, 70,100% Vdbench

Tests 1 and 2: Uniform Workloads, RAID Group and Block Size Scalability, Random and Sequential, SSD and SAS Test 1 measured the performance of 100% random reads and 100% random writes of 1-4 RAID Groups of SSD and SAS disks using various block sizes and thread counts (per LUN). Test 2 was the same except for sequential workloads.

The initial step was to configure 4 RAID Groups (20 disks) using RAID-5 (4D+1P) and then create a single 8GB LUN per RAID Group for both SSD and SAS disks. These 4 LUNs were evenly assigned to the four AMS 2500 ports (0A, 1A, 0E, 1E) in use. The AMS 2500 had its internal Hardware Load Balancing enabled. LUNs were driven by workloads on the controllers that managed them.

For Random workloads, IOmeter was used to drive the workloads on the HP server against raw volumes. The workload mixes included 100% Read and 100% Write, using block sizes of .5KB, 4KB, 16KB, 64KB, 256KB, and 1024KB. For reads, there were tests with 8 or 32 threads per LUN, and for writes there were tests with 1 or 8 threads per LUN. Tests were run against 1, 2, 3, and 4 LUNs (or 5, 10, 15, and 20 disks) using 1, 2, 3, or 4 ports.

For Sequential workloads, IOmeter was used to drive the workloads on the HP server against raw volumes. The workload mixes included 100% Read and 100% Write, using block sizes of .5KB, 4KB, 16KB, 64KB, 256KB, and 1024KB using 1 and 8 threads per LUN for reads and for writes. A special set of tests were run using a 256KB block size and 1 thread per LUN for read and writes. Tests were run against 1, 2, 3, and 4 LUNs (or 5, 10, 15, and 20 disks) using 1, 2, 3, or 4 ports.

Tests 3 and 4: Mixed Workloads, RAID Group and Block Size Scalability, Random and Sequential, SSD and SAS Test 3 measured the performance of 1-4 RAID Groups of SSD and SAS disks using mixed random workloads using several block sizes and having 8 threads per LUN. Test 4 was the same except for sequential workloads, larger block sizes, and only 1 thread per LUN.

The initial step was to configure 4 RAID Groups (20 disks) using RAID-5 (4D+1P) and then create a single 8GB LUN per RAID Group for both SSD and SAS disks. These 4 LUNs were evenly assigned to the four AMS 2500 ports (0A, 1A, 0E, 1E) in use. The AMS 2500 had its internal Hardware Load Balancing enabled. LUNs were driven by workloads on the controllers that managed them.

For Random workloads, Vdbench was used to drive the workloads on the HP server against raw volumes. The workload mixes included 100%, 75%, 50%, and 25% Read and 100% Write, using block sizes of 2KB, 4KB, 8KB and 16KB. All tests used 8 threads per LUN. Tests were run against 1, 2, 3, or 4 LUNs (or 5, 10, 15, and 20 disks) using 1, 2, 3, or 4 ports.

For Sequential workloads, IOmeter was configured to drive the workloads on the HP server against the raw volumes. The workload mixes included 100% Read and 100% Write, using block sizes of .5KB, 4KB, 16KB, 64KB, 256KB, and 1024KB using 8 threads per LUN for reads and for writes. A special set of tests were run using a 64KB RAID chunk size and 1 thread per LUN for read and writes. Tests were run against 1, 2, 3, or 4 LUNs (or 5, 10, 15, and 20 disks) using 1, 2, 3, or 4 ports.


Test 5: Single Workload, Single RAID Group, Thread Scalability, SSD and SAS Test 5 measured the performance of one RAID Group of SSD or SAS drives with one LUN of 133GB using a single 75% random read workload with an 8KB block size and a thread count scaling from 1 to 256 threads.

The initial step was to configure 1 RAID Group (5 disks) using RAID-5 (4D+1P) and then create a single 362GB LUN for both SSD and SAS disks. This one LUN was assigned to one AMS 2500 port (0A). The AMS 2500 had its internal Hardware Load Balancing enabled.

For Random workloads, Vdbench was used to drive the workloads on the HP server against one raw volume. The workload was 75% random read using a block size of 8KB. The tests scaled using used 1 to 256 threads on this LUN using one port.

Tests 6 to 9: Mixed Workloads, RAID Group and Block Size Scalability, Random and Sequential, SSD, HDP and non-HDP Test 6 measured the non-HDP performance of 4 RAID Groups of SSD drives using mixed random workloads with 8 133GB LUNs, an 8KB block size and 16 threads per LUN. Test 7 was the same except for mixed sequential workloads and a 1024KB block size. Test 8 measured the HDP performance of 4 RAID Groups of SSD drives using mixed random workloads with 8 133GB LUNs, an 8KB block size and 16 threads per LUN. Test 9 was the same except for mixed sequential workloads and a 1024KB block size.

The initial step was to configure 4 RAID Groups (20 disks) using RAID-5 (4D+1P) and then create two 133GB LUNs per RAID Group for both SSD and SAS drives. These 8 LUNs were evenly assigned to the four AMS 2500 ports (0A, 1A, 0E, 1E) in use. The AMS 2500 had its internal Hardware Load Balancing enabled. LUNs were driven by workloads on the controllers that managed them.

For Random workloads, Vdbench was used to drive the workloads on the HP server against raw volumes. The workload mixes included 100%, 75%, 50%, and 25% Read and 100% Write, using a block size of 8KB. All tests used 16 threads per LUN. Tests were run against 8 LUNs (20 drives) on four ports.

For Sequential workloads, Vdbench was used to drive the workloads on the HP server against raw volumes. The workload mixes included 100%, 75%, 50%, and 25% Read and 100% Write, using a block size of 1024KB. All tests used 16 threads per LUN. Tests were run against 8 LUNs (20 drives) on four ports.

Tests 10 and 11: Mixed Workloads, 4 RAID Groups, Random, SSD and SAS, HDP and non-HDP Test 10 measured the performance of 4 RAID Groups of SSD and SAS disks using mixed random workloads using a single 4KB block size and having various threads per LUN. There were two 133GB LUNs created per RAID Group, or eight in all. The Test 11 was the same except for the use of all 4 RAID Groups as Pools Volumes in an HDP configuration, with 8 DP-VOLs created from the Pool.

Unlike any of the previous test sets, a base set of tests within Test 10 and 11 that scaled the load on the drives, where the aggregate percent busy rate for the RAID Groups was 10%, 50%, 70%, 80%, 90%, and 100%. All of these were run using 8 threads per LUN or DPVOL. Another series of tests were also run where the percent busy rate was held at 100% and the thread counts varied, using 16, 32, 64, and 128 threads per LUN or DPVOL. This was to gauge the effects of load versus response time.

For Test 10, the initial step was to configure 4 RAID Groups (20 disks) using RAID-5 (4D+1P) and then create a two 133GB LUNs per RAID Group for both SSD and SAS disks. These 8 LUNs were evenly assigned to the four AMS 2500 ports (0A, 1A, 0E, 1E) in use. In Test 11, the system was reconfigured to


have the four SSD RAID Groups used as an HDP Pool, with 8 DPVOLs of 133GB created from that Pool. There were no similar tests performed on SAS disks.

The AMS 2500 had its internal Hardware Load Balancing enabled. LUNs were driven by workloads on the controllers that managed them.

For these Random workloads, Vdbench was used to drive the workloads on the HP server against raw volumes. The workload mixes included 100% and 70% and 100% Write, using a block size of 4KB. All tests used 8 threads per LUN. Tests were run against 8 LUNs (20 drives) or 8 DPVOLs.

AMS 2500 Test Results Summary Test 1 Results Random Read Summary Tables 4 and 5 are summaries of random read results with only the 4KB block size for either 8 or 32 threads per LUN. The tables for all read results are included in Appendix B. Again, these tests used block sizes of .5, 4, 16, 64, 256 and 1024KB in a 100% random read workload against one, two, three, or four LUNs (one per RAID Group). Column 8 (“SSD: SAS”) shows the ratio of SSD over SAS performance. Column 3 (“threads”) shows the total threads in use during the test. Columns 4 and 5 show the SSD values, and columns 7 and 8 show the matching SAS values. Note the large overall increase in IOPS (but also in the response times) when increasing the workload from 8 to 32 threads per LUN. For these workloads SSD drives are about 12x faster than SAS disks.

Table 4. Random Read Results with 8 Threads per LUN

Random 100% Read

8 threads/LU 4KB RAID‐5 4+1 SSD SAS SSD : SAS

Drives LUNs Threads IOPS RT [msec] IOPS RT [msec] X:1

5 1 8 15,148 0.53 1,278 6.26 11.8

10 2 16 30,437 0.52 2,562 6.24 11.9

15 3 24 45,298 0.53 3,851 6.23 11.8

20 4 32 60,086 0.53 5,128 6.24 11.7

Table 5. Random Read Results with 32 Threads per LUN

Random 100% Read

32 threads/LU 4KB RAID‐5 4+1 SSD SAS SSD : SAS


5 1 32 24,191 1.32 1,969 16.25 12.3

10 2 64 48,501 1.32 3,952 16.19 12.3

15 3 96 72,262 1.33 5,931 16.18 12.2

20 4 128 96,125 1.33 7,893 16.21 12.2


Random Write Summary Tables 6 and 7 are summaries of random write results with the 4KB block size for either 1 or 8 threads per LUN. The tables for all write results are included in Appendix A. Again, these tests used block sizes of .5, 4, 16, 64, 256 and 1024KB in a 100% random write workload against one, two, three, or four LUNs (one per RAID Group). Column 8 (“SSD: SAS”) shows the ratio of SSD over SAS performance. Column 3 (“threads”) shows the total threads in use during the test. Columns 4 and 5 show the SSD values, and columns 7 and 8 show the matching SAS values. Note the large overall increase in IOPS (but also in the response times) when increasing the workload from 1 to 8 threads per LUN. For these workloads SSD drives are about 7x or 9x faster than SAS disks.

Table 6. Random Write Results with 1 Thread per LUN

Random 100% Write

1 thread/LU 4KB RAID‐5 SSD SAS SSD : SAS


5 1 1 4,498 0.20 623 1.60 7.2

10 2 2 10,198 0.21 1,253 1.60 8.1

15 3 3 12,767 0.22 1,903 1.58 6.7

20 4 4 16,687 0.22 2,533 1.58 6.6

Table 7. Random Write Results with 8 Threads per LUN

Random 100% Write

8 threads/LU 4KB RAID‐5 SSD SAS SSD : SAS


5 1 8 6,127 1.06 618 12.93 9.9

10 2 16 12,269 1.07 1,260 12.70 9.7

15 3 24 17,626 1.16 1,914 12.53 9.2

20 4 32 23,026 1.20 2,536 12.62 9.1

Test 2 Results Sequential Read Summary Tables 8 and 9 are summaries of sequential read results with only the 256KB block size for either 1 or 8 threads per LUN. The tables with all read results are included in Appendix C. Again, these tests used block sizes of .5, 4, 16, 64, 256 and 1024KB in a 100% sequential read workload against one, two, three, or four LUNs (one per RAID Group).

These results show that the use of 8 threads per LUN instead of 1 thread per LUN slightly increased total throughput but at a cost of large increase in response time. Note that response time is not usually a consideration for sequential workloads, but it does illustrate the effect of overdriving the LUNs. Also note the fairly small difference (5-15%) with 1 thread per LUN between the use of SSDs and SAS drives in this workload. Column 8 shows the ratio (as a percent) of the SSD result divided by the SAS result.


Table 8. Sequential Read Results with 1 Thread per LUN

Sequential Read

1 thread/LUN 256KB RAID‐5 4+1 SSD SAS SSD : SAS

Drives LUNs Threads MB/s RT [msec] MB/s RT [msec] X:1

5 1 1 321.2 0.8 278.7 0.9 1.2

10 2 2 623.5 0.8 576.6 0.9 1.1

15 3 3 910.7 0.8 868.0 0.9 1.0

20 4 4 1224.6 0.8 1,171.6 0.9 1.0

Table 9. Sequential Read Results with 8 Threads per LUN

Sequential Read

8 threads/LUN 256KB RAID‐5 4+1 SSD SAS SSD : SAS


5 1 8 380.5 5.3 293.7 6.8 1.3

10 2 16 761.4 5.3 624.2 6.4 1.2

15 3 24 1142.0 5.3 951.9 6.3 1.2

20 4 32 1535.9 20.8 1,273.9 6.3 1.2

Sequential Write Summary Tables 10 and 11 are summaries of sequential write results with only the 256KB block size for either 1 or 8 threads per LUN. The tables for all write results are included in Appendix B. Again, these tests used block sizes of .5, 4, 16, 64, 256 and 1024KB in a 100% sequential write workload against one, two, three, or four LUNs (one per RAID Group).

These results show that the use of 8 threads per LUN instead of 1 thread per LUN slightly increased total throughput but at a cost of large increase in response time. Note that response time is not usually a consideration for sequential workloads, but it does illustrate the effect of overdriving the LUNs. Also note the small difference (7-13%) between the use of SSDs and SAS drives in this workload. Column 8 shows the ratio (as a percent) of the SSD result divided by the SAS result.

Table 10. Sequential Write Results with 1 Thread per LUN

Sequential Write

1 thread/LUN 256KB RAID‐5 4+1 SSD SAS SSD : SAS


5 1 1 257.9 1.0 227.4 1.1 1.1

10 2 2 506.6 1.0 454.9 1.1 1.1

15 3 3 716.7 1.0 665.2 1.1 1.1

20 4 4 931.7 1.1 865.8 1.2 1.1


Table 11. Sequential Write Results with 8 Threads per LUN

Sequential Write

8 threads/LUN 256KB RAID‐5 4+1 SSD SAS SSD : SAS


5 1 8 265.3 7.5 232.9 8.5 1.1

10 2 16 528.7 7.5 468.2 8.4 1.1

15 3 24 754.8 7.9 683.9 8.7 1.1

20 4 32 965.9 8.2 889.7 8.9 1.1

Test 3 Results Observations

There is a lot of detailed data presented in the Appendix D below. However, the following summary may provide the best overall idea on small block random workloads on SSD. This summary show the results of the 5, 10, 15 and 20 drive tests using just the block size of 8KB with the RAID chunk size of 256KB (default).

8KB Block Size

As can be seen below there is a linear increase in performance as the test scaled from 5, 10, 15 and then 20 drives using RAID-5 (4d+1P). There was no real difference in the response times.

Chart 1. IOPS Results

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

100 75 50 25 0

IOPS

Random Read %

5‐20 SSD, 8KB Block Size, IOPS

5 SSD

10 SSD

15 SSD

20 SSD


Chart 2. Response Times

Test 4 Results Observations

There is a lot of data presented in Appendix E for these tests. However, the following summary may provide the best overall idea on sequential workloads on SSD and the effect of changing the RAID chunk size from the default of 256KB down to 64KB. Normally, the response time is not considered with sequential workloads, but here they provide some interesting insight into the change of behavior with the two RAID chunk sizes. These three summaries show the results of the 20 drive tests using block sizes of 64KB, 256KB, and 512KB with RAID chunk sizes of 64KB and 256KB (default).

64KB Block Size

As can be seen below there is no effect on performance or response time due to the different RAID chunk sizes.

Table 12. Sequential Results with 64KB Block Size

Sequential 20 SSD

R5 4d+1p 4 Threads

64KB Block

256KB Chunk 64KB Chunk

Read % MB/sec RT [msec] MB/sec RT [msec]

100 971.9 0.3 972.9 0.3

75 626.0 0.4 566.7 0.4

50 503.9 0.5 484.1 0.5

25 446.7 0.6 412.5 0.6

0 714.9 0.3 755.5 0.3

0.0

0.2

0.4

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1.6

100 75 50 25 0

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e (MS)

Random Read %

5‐20 SSD, 8KB Block Size, Response Time

5 SSD

10 SSD

15 SSD

20 SSD


Chart 3. Throughput by RAID Chunk Size


256KB Block Size

As can be seen below, the smaller 64KB RAID chunk size has a large advantage over the default 256KB chunk except for the 100% read or write cases where they are equal. The presence of mixed workloads gives a large performance and response time advantage to the smaller chunk size.

0

200

400

600

800

1000

1200

100 75 50 25 0

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Sequential Read %

20 SSD, 64KB Block Size

256KB Chunk

64KB Chunk

0.0

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100 75 50 25 0

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e (MS)

Sequential Read %


256KB Chunk

64KB Chunk



Sequential 20 SSD

R5 4d+1p 4 Threads

256KB Block



100 1218.8 0.8 1231.7 0.8

75 241.0 4.2 789.4 1.3

50 117.9 8.5 596.1 1.7

25 97.6 10.4 486.3 2.1

0 938.9 1.1 1040.0 1.0



0

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100 75 50 25 0

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Sequential Read %


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64KB Chunk

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Sequential Read %


256KB Chunk

64KB Chunk


512KB Block Size

As can be seen below, the smaller 64KB RAID chunk size has a large advantage over the default except for the 100% read or write cases. The presence of mixed workloads gives a large performance and response time advantage to the smaller chunk size.


Sequential 20 SSD

R5 4d+1p 4 Threads

512KB Block



100 1257.4 1.6 1282.2 1.6

75 347.7 5.8 851.2 2.3

50 189.7 10.6 631.2 3.2

25 144.2 13.9 502.0 4.0

0 960.3 2.1 1032.0 1.9


0

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1200

1400

100 75 50 25 0

MB/sec

Sequential Read %


256KB Chunk

64KB Chunk



Test 5 Results These tests used a single RAID Group of either SSD or SAS drives. There was a single LUN of 362GB, and a workload of 75% random read with a block size of 8KB was used, with a scaling of the thread counts from 1 to 256 as shown below. These also include the controller percent busy rates (for the single controller in use).

The SAS drive tests didn’t cause much CPU usage until a high thread count of 64 for that LUN was reached. The 5 SSD drive tests showed a heavy CPU usage from a thread count of 4 and up. Note that for SSD, at the 16 thread level, the CPU % Busy was 68%. Yet in Test 6, at the 75% test with 16 threads, the CPU % Busy was 58% with 20 drives and three times the IOPS rate (9570 IOPS versus 28191). So it appears that the CPU % Busy rates with SSDs don’t track with the number of drives or the loads, and should only be used as a rough guide relative to SAS drives.

Table 15. SSD 5-Disk Thread Scaling

Random Read 75%

8KB block RAID‐5 4d+1p 5 SSD 362GB LUN

Threads IOPS MB/s RT [msec] CPU usage

1 1555 12.2 0.6 1%

2 2723 21.3 0.7 12%

4 4420 34.5 0.9 28%

8 6739 52.7 1.2 49%

16 9570 74.8 1.7 68%

32 12230 95.5 2.6 80%

64 13753 107.4 4.7 95%

128 11405 89.1 11.2 100%

256 8874 69.3 28.8 90%

0

2

4

6

8

10

12

14

16

100 75 50 25 0

Respone Tim

e (MS)

Sequential Read %


256KB Chunk

64KB Chunk


Table 16. SAS 5-Disk Thread Scaling

Random Read 75%

8KB block RAID‐5 4d+1p 5 SAS 362GB LUN

Threads IOPS MB/s RT [msec] CPU usage

1 165 1.3 6.1 1%

2 272 2.1 7.4 1%

4 400 3.1 10.0 1%

8 534 4.2 15.0 1%

16 661 5.2 24.2 1%

32 778 6.1 41.1 3%

64 861 6.7 74.4 82%

128 976 7.6 131.1 94%

256 1008 7.9 254.0 95%

Test 6 Results (non-HDP) Random Mixed Workloads Using 4 SSD RAID Groups, 8 133GB LUNs, and 16 Threads Note the rapid drop in IOPS with a write element in the workload. Also note how well the response time holds up for all write levels.

Table 17. SSD Mixed Random Workload Results with 20 Drives

Random 8kb Non‐HDP

SSD (20) R5 4d+1p 8 133GB LUNs 16 threads

Read % IOPS MB/s RT [msec] CPU Usage

100 44,674 349.0 0.7 55%

75 28,191 220.2 1.1 58%

50 25,714 200.9 1.2 73%

25 26,376 206.1 1.2 92%

0 22,452 175.4 1.4 98%

Test 7 Results (HDP) Random Workloads Using HDP with 4 SSD RAID Groups, 8 133GB DPVOLs, and 16 Threads These workloads used 8 DPVOLs instead of 8 LUNs as above.

Table 18. SSD Mixed Random Workload Results with 20 Drives and HDP

Random 8kb HDP


Read % IOPS MB/s RT [msec] CPU Usage

100 39,688 310.1 0.8 65%

75 25,415 198.6 1.3 69%

50 22,708 177.4 1.4 83%

25 21,603 168.8 1.5 95%

0 17,438 136.2 1.8 99%


Test 8 Results (non-HDP) Sequential Workloads Using 4 SSD RAID Groups, 8 133GB LUNs, 16 Threads The performance with 50% to 0% Sequential reads stayed around 1GB/s. The 100% Read test shows that there is at least a 57% cache hit rate occurring in the server, as this is a 596 MB/s per path result. Note that 4Gbit/s FC paths top out at about 380 MB/sec.

Table 19. SSD Mixed Sequential Workload Results with 20 Drives

Sequential 1024k Non‐HDP


Read % MB/s RT [msec] CPU Usage

100 2386.7 13.4 33%

75 1470.3 21.8 46%

50 1088.2 29.4 57%

25 957.7 33.4 69%

0 1084.2 29.5 98%

Test 9 Results (HDP) Sequential Workloads Using HDP with 4 SSD RAID Groups, 8 133GB DPVOLs, and 16 Threads These workloads used 8 DPVOLs instead of 8 LUNs as above. Also, the 100% Read result indicates at least a 10% cache hit rate in the server with the average 415MB/s per path result.

Table 20. SSD Mixed Sequential Workload Results with 20 Drives and HDP

Sequential 1024k HDP


Read % MB/s RT [msec] CPU Usage

100 1661.2 19.3 24%

75 1129.7 28.4 38%

50 883.3 36.3 54%

25 836.5 38.3 71%

0 1096.2 29.2 100%

Test 10 Results Random Workloads Using 4 RAID Groups, 4KB blocks and 8 133GB LUNs This set of non-HDP tests has two parts to look at load scaling as opposed to LUN scaling. The first part of the tests uses up to 8 threads per LUN, but the workload throttles the overall amount of dispatched threads in such a way as to produce a certain aggregate SSD drive percent busy rate. The tests stepped from 10%, 50%, 70%, 80%, and then 90%. The next set of tests ran at a constant 100% load, but increased the threads per LUN counts from 8, 16, 32, 64 and then 128. One set of tests used 100% random read as the workload, the second used 100% random write, and the last set used 70% random read plus 30% sequential read in a mixed workload.

In the 100% random read tests, there was a steady performance gain as the workload increased until the 64 threads per LUN (i.e. 512 overall) point when the aggregate controller busy rates likely hit 99% (this data was not captured).


Table 21. Random Read Results

100% Random Read 4KB

Non‐HDP SSD (20) R5 4d+1p 8 LUNs 133GB LUNs

Disk % Busy Threads/LUN IOPS MB/s RT [msec]

10% 8 6,197 24.2 0.7

50% 8 30,608 119.6 0.6

70% 8 42,794 167.2 0.6

80% 8 48,891 191.0 0.5

90% 8 55,090 215.2 0.5

100% 8 60,424 236.0 0.5

100% 16 88,981 347.6 0.7

100% 32 111,285 434.7 1.1

100% 64 125,238 489.2 1.6

100% 128 123,714 483.3 2.6

In the 100% random write tests, there was a steady performance gain as the workload increased until the 100% busy test using 8 threads per LUN (i.e. 64 overall) point when the ability of the SSD drives to accept writes hit the limit.

Table 22. Random Write Results

100% Random Write 4KB


Disk % Busy Threads/LUN IOPS MB/s RT [msec]

10% 8 2,599 10.2 0.2

50% 8 12,995 50.8 0.3

70% 8 18,100 70.7 0.4

80% 8 20,694 80.8 0.6

90% 8 23,318 91.1 0.7

100% 8 25,623 100.1 1.2

100% 16 23,398 91.4 2.7

100% 32 21,337 83.4 6.0

100% 64 16,407 64.1 15.6

100% 128 11,480 44.8 44.6

In the 70/30% tests, there was a steady performance gain as the workload increased until the 100% busy test using 32 threads per LUN (i.e. 256 overall) point when the ability of the SSD drives to accept writes along with the reads hit the limit.


Table 23. Mixed Random and Sequential Results

70% Random Read, 30% Sequential Read 4KB


IOPS/Max IOPS Threads/LUN IOPS MB/s RT [msec]

10% 8 2,900 11.3 0.5

50% 8 14,508 56.7 0.7

70% 8 20,321 79.4 0.9

80% 8 23,227 90.7 1.0

90% 8 26,108 102.0 1.0

100% 8 28,523 111.4 1.1

100% 16 40,252 157.2 1.6

100% 32 51,715 202.0 2.5

100% 64 32,438 126.7 7.9

100% 128 26,495 103.5 19.3

Test 11 Results (HDP) Random Workloads Using HDP with 4 RAID Groups, 4KB Blocks and 8 133GB DPVOLs This set of tests is the same as above but uses 8 HDP DPVOLs rather than 8 standard LUNs (2 per RAID Group). The four RAID Groups were used in one HDP Pool.

In the 100% random read tests, there was a steady performance gain as the workload increased until the 64 threads per LUN (i.e. 512 overall) point when the aggregate controller busy rates hit 99%.

Table 24. Random Read Results with HDP

100% Random Read 4KB

HDP SSD (20) R5 4d+1p 8 LUNs 133GB LUNs

Disk % Busy Threads/LUN IOPS MB/s RT [msec] % CPU usage

10% 8 5,407 21.1 0.8 1

50% 8 26,699 104.3 0.6 41

70% 8 37,302 145.7 0.6 60

80% 8 42,583 166.3 0.6 68

90% 8 47,990 187.5 0.6 75

100% 8 53,002 207.0 0.6 81

100% 16 74,747 292.0 0.8 93

100% 32 88,647 346.3 1.4 97

100% 64 96,295 376.2 2.6 99

100% 128 96,096 375.4 5.2 99

In the 100% random write tests, there was a steady performance gain as the workload increased until the performance knee with the 100% busy test using 8 threads per LUN (i.e. 64 overall) point when the ability of the SSD drives to accept writes hit the limit.


Table 25. Random Write Results with HDP

100% Random Write 4KB



10% 8 1,894 7.4 0.6

50% 8 9,094 35.5 0.6

70% 8 12,822 50.1 0.7

80% 8 14,635 57.2 0.8

90% 8 16,437 64.2 0.9

100% 8 18,256 71.3 1.1

100% 16 18,648 72.8 3.4

100% 32 15,130 59.1 8.5

100% 64 18,868 73.7 13.6

100% 128 17,179 67.1 29.9

In the 70/30% tests, there was a steady performance gain as the workload increased until the 100% busy test using 32 threads per LUN (i.e. 256 overall) point when the ability of the SSD drives to accept writes along with the reads hit the limit.

Table 26. Mixed Random and Sequential Results with HDP

70% Random Read, 30% Sequential Read 4KB



10% 8 2,701 10.6 0.9

50% 8 13,513 52.8 1.0

70% 8 18,916 73.9 1.0

80% 8 21,495 84.0 1.1

90% 8 24,211 94.6 1.1

100% 8 26,631 104.0 1.2

100% 16 36,132 141.1 1.8

100% 32 42,615 166.5 3.0

100% 64 41,799 163.3 6.1

100% 128 31,613 123.5 16.1

This table summarizes the performance knees for each test as a comparison between non-HDP and HDP. In general there was a performance advantage of from 19% to 30% for the non-HDP configuration. However, these tests created uniform workloads on all 8 LUNs or DPVOLs, and HDP is primarily intended to smooth out RAID Group hot spots from having fairly skewed host loads, as is the usual case on production systems.

Conclusions In closing, a few general observations can be made when evaluating the performance of SSD drives on the AMS 2500.

For random workloads, one can see that as the write component was introduced, there was a clear fall-off in performance due to the large disparity in read to write performance of SSD technology in general. As expected, the difference with random workloads between equal numbers of SSD drives and SAS drives


was also very large. However, the array can only support a small number of SSD drives, hence a small total usable capacity.

For large block sequential workloads, there was a fairly small advantage for the SSD drives. Due to their high cost and limited capacity, SSD drives should not be used instead of SAS for predominantly sequential workloads.

Assuming a relatively small SSD capacity the use of HDP on an SSD pool would likely not be the preferred approach. Since the SSD capacity is small the administrator will have to take steps to isolate the most active workloads onto the smallest storage footprint. SSD also appears to not suffer from the traditional hotspot degradation problem until it is at the outer edges of its performance capabilities. Therefore deploying SSD would seem to not be able to take advantage of HDP’s benefit trifecta: Space savings, easy of provisioning, and avoiding hot spots.

The other issue to consider is the rate at which SSDs consume internal bandwidths of the array. Perhaps a good rule of thumb to follow is that each SSD drive uses up array bandwidth at the ratio of 12-to-1 of SAS drives for 4KB block random read environments. For random writes, this ratio varies considerably by the block size, with a 4KB block showing about a 9-to-1 ratio of SSD drives to SAS drives. These results suggest that using 30 SSD drives for mostly random read environments displaces 360 SAS drives or 270 SAS drives for random writes. One cannot, for example, configure an array with 30 SSDs and 300 SAS drives with the expectation that both types can be driven hard simultaneously.


APPENDIX A. Test Configuration Details Test information

Table 1: Test Details

Test Period Report Date Location Tester

Nov Dec 2009 February 2010 RSD Japan Yusuke Nishihara

Host Configuration

Table 2: Test Server Configuration

Server Operating System CPU Memory HBA

HP DL585 G2 Windows 2003 Server SP2 8 x 3GHz

Opteron 8222se 16GB RAM 2 QLE2462 HBA

Storage Configuration

Table 3: AMS 2500 Configuration

Storage Microcode Number of host paths

Total Cache Size

License keys enabled?

Load Balancing Enabled

AMS 2500 0846/B‐H 1‐4 4Gbit/s 16GB No Yes

Type of Disk Size of Disk # of Disks RPM

SAS 146GB 20 15,000

SSD 200GB 20 ‐

RAID Level

RAID Configuration Number of Number of Size of each LUN Chunk size Spares RAID Groups LUNs

RAID 5 4D + 1P 4 4, 8 8, 133, 362GB 256KB 0


APPENDIX B. Test-1 Full Results 5 Drives

Random Read

R5 4+1 x1

8 threads SSD 5 drives

Random Read

R5 4+1 x1


Block (KB) IOPS MB/s RT

[msec] SSD/SAS IOPS Block (KB) IOPS MB/s

RT [msec]

SSD/SAS IOPS

0.5 22,840 11.2 0.35 1739% 0.5 36,995 18.1 0.86 1806%

4 15,148 59.2 0.53 1185% 4 24,191 94.5 1.32 1228%

16 8,512 133.0 0.94 728% 16 12,347 192.9 2.59 698%

64 3,958 247.4 2.02 442% 64 4,757 297.3 6.73 369%

256 1,307 326.7 6.12 266% 256 1,430 357.5 22.38 229%

1024 375 375.2 21.32 213% 1024 388 387.8 82.52 202%

Random Read

R5 4+1 x1

8 threads SAS 5 drives

Random Read

R5 4+1 x1



[msec] SAS/SSD IOPS Block (KB) IOPS MB/s

RT [msec]

SAS/SSD IOPS

0.5 1,313 0.6 6.09 5.7% 0.5 2,048 1.0 15.62 5.5%

4 1,278 5.0 6.26 8.4% 4 1,969 7.7 16.25 8.1%

16 1,169 18.3 6.84 13.7% 16 1,769 27.6 18.09 14.3%

64 896 56.0 8.93 22.6% 64 1,289 80.6 24.82 27.1%

256 490 122.6 16.31 37.5% 256 626 156.4 51.13 43.8%

1024 176 176.4 45.34 47.0% 1024 192 192.2 166.49 49.6%

Random Write

R5 4+1 x1 1 thread SSD 5 drives

Random Write

R5 4+1 x1




RT [msec]

SSD/SAS IOPS

0.5 5,058 2.5 0.20 762% 0.5 7,553 3.7 1.06 1137%

4 4,498 17.6 0.22 722% 4 6,127 23.9 1.31 992%

16 3,209 50.1 0.31 618% 16 3,397 53.1 2.35 652%

64 1,174 73.4 0.85 383% 64 1,191 74.4 6.72 395%

256 322 80.5 3.10 256% 256 297 74.3 26.92 239%

1024 19 18.9 53.03 60% 1024 99 98.8 80.95 154%

Random Write

R5 4+1 x1 1 thread SAS 5 drives

Random Write

R5 4+1 x1




RT [msec]

SAS/SSD IOPS

0.5 664 0.3 1.51 13.1% 0.5 665 0.3 12.02 8.8%

4 623 2.4 1.60 13.9% 4 618 2.4 12.93 10.1%

16 519 8.1 1.92 16.2% 16 521 8.1 15.36 15.3%

64 307 19.2 3.26 26.1% 64 301 18.8 26.54 25.3%

256 126 31.5 7.93 39.1% 256 124 31.1 64.25 41.9%

1024 32 31.5 31.73 167.1% 1024 64 64.1 124.70 64.8%


10 Drives

Random Read

R5 4+1 x2


Random Read

R5 4+1 x2




RT [msec]

SSD/SAS IOPS

0.5 45,910 22.4 0.35 1739% 0.5 74,256 36.3 0.86 1810%

4 30,437 118.9 0.52 1188% 4 48,501 189.5 1.32 1227%

16 16,951 264.9 0.94 721% 16 24,732 386.4 2.59 695%

64 7,922 495.1 2.02 439% 64 9,521 595.1 6.72 367%

256 2,612 652.9 6.13 266% 256 2,858 714.6 22.39 227%

1024 751 750.7 21.31 212% 1024 774 774.3 82.65 201%

Random Read

R5 4+1 x2


Random Read

R5 4+1 x2




RT [msec]

SAS/SSD IOPS

0.5 2,640 1.3 6.06 5.8% 0.5 4,103 2.0 15.60 5.5%

4 2,562 10.0 6.24 8.4% 4 3,952 15.4 16.19 8.1%

16 2,351 36.7 6.81 13.9% 16 3,557 55.6 17.99 14.4%

64 1,803 112.7 8.87 22.8% 64 2,591 161.9 24.70 27.2%

256 982 245.4 16.29 37.6% 256 1,261 315.1 50.75 44.1%

1024 354 353.6 45.24 47.1% 1024 385 385.0 166.18 49.7%

Random Write

R5 4+1 x2


Random Write

R5 4+1 x2




RT [msec]

SSD/SAS IOPS

0.5 10,198 5.0 0.21 758% 0.5 15,145 7.4 1.07 1115%

4 9,098 35.5 0.22 726% 4 12,269 47.9 1.30 974%

16 6,405 100.1 0.31 606% 16 6,802 106.3 2.35 642%

64 2,358 147.4 0.85 390% 64 2,391 149.5 6.69 399%

256 654 163.6 3.06 256% 256 600 150.1 26.64 243%

1024 38 37.8 52.77 56% 1024 200 199.8 80.07 163%

Random Write

R5 4+1 x2


Random Write

R5 4+1 x2




RT [msec]

SAS/SSD IOPS

0.5 1,346 0.7 1.49 13.2% 0.5 1,358 0.7 11.78 9.0%

4 1,253 4.9 1.60 13.8% 4 1,260 4.9 12.70 10.3%

16 1,057 16.5 1.89 16.5% 16 1,059 16.5 15.12 15.6%

64 604 37.8 3.31 25.6% 64 599 37.4 26.71 25.0%

256 256 64.0 7.80 39.1% 256 247 61.8 64.70 41.2%

1024 67 67.3 29.70 178.1% 1024 122 122.4 130.56 61.3%


15 Drives Random Read

R5 4+1 x3


Random Read

R5 4+1 x3




RT [msec]

SSD/SAS IOPS

0.5 67,592 33.0 0.35 1704% 0.5 108,783 53.1 0.88 1769%

4 45,298 176.9 0.53 1176% 4 72,262 282.3 1.33 1218%

16 25,293 395.2 0.95 716% 16 37,095 579.6 2.59 695%

64 11,879 742.4 2.02 438% 64 14,213 888.3 6.75 366%

256 3,903 975.7 6.15 264% 256 4,249 1,062.2 22.59 225%

1024 1,123 1,122.5 21.38 211% 1024 1,161 1,161.4 82.66 201%

Random Read

R5 4+1 x3


Random Read

R5 4+1 x3




RT [msec]

SAS/SSD IOPS

0.5 3,968 1.9 6.05 5.9% 0.5 6,149 3.0 15.61 5.7%

4 3,851 15.0 6.23 8.5% 4 5,931 23.2 16.18 8.2%

16 3,532 55.2 6.79 14.0% 16 5,339 83.4 17.98 14.4%

64 2,711 169.4 8.85 22.8% 64 3,884 242.8 24.71 27.3%

256 1,476 369.0 16.26 37.8% 256 1,891 472.7 50.76 44.5%

1024 532 532.4 45.07 47.4% 1024 578 577.7 166.14 49.7%

Random Write

R5 4+1 x3


Random Write

R5 4+1 x3




RT [msec]

SSD/SAS IOPS

0.5 14,490 7.1 0.22 710% 0.5 21,311 10.4 1.16 1041%

4 12,767 49.9 0.23 671% 4 17,626 68.9 1.36 921%

16 9,327 145.7 0.32 581% 16 9,612 150.2 2.49 586%

64 3,470 216.9 0.86 381% 64 3,514 219.6 6.83 388%

256 909 227.1 3.30 238% 256 863 215.6 27.80 229%

1024 57 57.3 51.69 58% 1024 293 293.5 81.76 151%

Random Write

R5 4+1 x3


Random Write

R5 4+1 x3




RT [msec]

SAS/SSD IOPS

0.5 2,040 1.0 1.47 14.1% 0.5 2,046 1.0 11.72 9.6%

4 1,903 7.4 1.58 14.9% 4 1,914 7.5 12.53 10.9%

16 1,605 25.1 1.87 17.2% 16 1,640 25.6 14.62 17.1%

64 910 56.9 3.30 26.2% 64 907 56.7 26.47 25.8%

256 381 95.3 7.85 42.0% 256 376 94.0 63.80 43.6%

1024 99 99.1 29.84 173.0% 1024 194 193.9 123.62 66.1%


20 Drives Random Read

R5 4+1 x4


Random Read

R5 4+1 x4




RT [msec]

SSD/SAS IOPS

0.5 89,877 43.9 0.36 1700% 0.5 143,314 70.0 1.00 1752%

4 60,086 234.7 0.53 1172% 4 96,125 375.5 1.33 1218%

16 33,819 528.4 0.95 717% 16 49,479 773.1 2.59 696%

64 15,854 990.9 2.02 439% 64 18,920 1,182.5 6.76 365%

256 5,195 1,298.6 6.16 264% 256 5,644 1,411.0 22.68 224%

1024 1,495 1,494.9 21.40 211% 1024 1,548 1,548.5 82.66 201%

Random Read

R5 4+1 x4


Random Read

R5 4+1 x4




RT [msec]

SAS/SSD IOPS

0.5 5,286 2.6 6.05 5.9% 0.5 8,182 4.0 15.64 5.7%

4 5,128 20.0 6.24 8.5% 4 7,893 30.8 16.21 8.2%

16 4,714 73.7 6.79 13.9% 16 7,109 111.1 18.00 14.4%

64 3,612 225.8 8.86 22.8% 64 5,185 324.0 24.69 27.4%

256 1,966 491.6 16.27 37.9% 256 2,524 630.9 50.71 44.7%

1024 709 709.4 45.10 47.5% 1024 770 769.7 166.27 49.7%

Random Write

R5 4+1 x4


Random Write

R5 4+1 x4




RT [msec]

SSD/SAS IOPS

0.5 18,833 9.2 0.22 691% 0.5 27,573 13.5 1.20 1008%

4 16,687 65.2 0.24 659% 4 23,026 89.9 1.39 908%

16 12,209 190.8 0.33 573% 16 12,566 196.3 2.55 584%

64 4,574 285.9 0.87 379% 64 4,643 290.2 6.89 388%

256 1,187 296.6 3.37 234% 256 1,152 288.0 27.78 230%

1024 74 73.9 54.07 59% 1024 389 389.2 82.11 145%

Random Write

R5 4+1 x4


Random Write

R5 4+1 x4




RT [msec]

SAS/SSD IOPS

0.5 2,724 1.3 1.47 14.5% 0.5 2,735 1.3 11.70 9.9%

4 2,533 9.9 1.58 15.2% 4 2,536 9.9 12.62 11.0%

16 2,130 33.3 1.88 17.4% 16 2,152 33.6 14.86 17.1%

64 1,208 75.5 3.31 26.4% 64 1,197 74.8 26.73 25.8%

256 508 126.9 7.87 42.8% 256 502 125.4 63.79 43.5%

1024 124 124.5 31.79 168.4% 1024 268 267.9 119.42 68.8%


APPENDIX C. Test-2 Full Results 5 Drives

Sequential Read


Sequential Read

R5 4+1 x1




RT [msec]

SSD/SAS IOPS

0.5 14,472 7.1 0.07 119% 0.5 74,769 36.5 0.11 114%

4 11,276 44.0 0.09 103% 4 50,824 198.5 0.16 108%

16 8,693 135.8 0.11 111% 16 19,447 303.9 0.41 109%

64 3,820 238.7 0.26 108% 64 5,612 350.7 1.43 119%

256 1,285 321.2 0.78 115% 256 1,522 380.5 5.26 130%

1024 337 336.6 2.97 116% 1024 385 384.8 20.79 130%

Sequential Read


Sequential Read

R5 4+1 x1




RT [msec]

SAS/SSD IOPS

0.5 12,195 6.0 0.08 84.3% 0.5 65,518 32.0 0.12 87.6%

4 10,979 42.9 0.09 97.4% 4 47,094 184.0 0.17 92.7%

16 7,805 122.0 0.13 89.8% 16 17,874 279.3 0.45 91.9%

64 3,551 221.9 0.28 93.0% 64 4,709 294.3 1.70 83.9%

256 1,115 278.7 0.90 86.8% 256 1,175 293.7 6.81 77.2%

1024 290 290.2 3.44 86.2% 1024 295 294.9 27.13 76.7%

Sequential Write


Sequential Write

R5 4+1 x1




RT [msec]

SSD/SAS IOPS

0.5 9,899 4.8 0.10 109% 0.5 39,175 19.1 0.20 101%

4 8,202 32.0 0.12 93% 4 31,220 122.0 0.26 100%

16 6,293 98.3 0.16 105% 16 16,887 263.9 0.47 117%

64 2,889 180.6 0.35 96% 64 4,252 265.7 1.88 113%

256 1,032 257.9 0.97 113% 256 1,061 265.3 7.51 114%

1024 266 266.2 3.76 113% 1024 266 265.5 30.13 114%

Sequential Write


Sequential Write

R5 4+1 x1




RT [msec]

SAS/SSD IOPS

0.5 9,062 4.4 0.11 91.5% 0.5 38,688 18.9 0.21 98.8%

4 8,788 34.3 0.11 107.1% 4 31,314 122.3 0.25 100.3%

16 5,978 93.4 0.17 95.0% 16 14,426 225.4 0.55 85.4%

64 3,006 187.9 0.33 104.0% 64 3,749 234.3 2.09 88.2%

256 910 227.4 1.10 88.2% 256 931 232.9 8.45 87.8%

1024 235 235.5 4.25 88.4% 1024 233 233.0 34.31 87.8%


10 Drives

Sequential Read

R5 4+1 x2


Sequential Read

R5 4+1 x2




RT [msec]

SSD/SAS IOPS

0.5 25,882 12.6 0.08 105% 0.5 137,228 67.0 0.12 115%

4 23,041 90.0 0.09 106% 4 101,538 396.6 0.16 107%

16 16,213 253.3 0.12 105% 16 38,907 607.9 0.41 103%

64 7,706 481.6 0.26 106% 64 11,240 702.5 1.42 113%

256 2,494 623.5 0.80 108% 256 3,046 761.4 5.25 122%

1024 678 677.6 2.95 110% 1024 770 770.1 20.78 123%

Sequential Read

R5 4+1 x2


Sequential Read

R5 4+1 x2




RT [msec]

SAS/SSD IOPS

0.5 24,719 12.1 0.08 95.5% 0.5 119,421 58.3 0.13 87.0%

4 21,808 85.2 0.09 94.7% 4 94,643 369.7 0.17 93.2%

16 15,441 241.3 0.13 95.2% 16 37,625 587.9 0.42 96.7%

64 7,291 455.7 0.27 94.6% 64 9,986 624.1 1.60 88.8%

256 2,306 576.6 0.87 92.5% 256 2,497 624.2 6.41 82.0%

1024 618 617.6 3.24 91.1% 1024 626 625.6 25.58 81.2%

Sequential Write

R5 4+1 x2


Sequential Write

R5 4+1 x2




RT [msec]

SSD/SAS IOPS

0.5 18,634 9.1 0.11 104% 0.5 77,896 38.0 0.20 102%

4 16,735 65.4 0.12 104% 4 62,248 243.2 0.26 100%

16 12,060 188.4 0.17 103% 16 33,896 529.6 0.47 117%

64 5,885 367.8 0.34 102% 64 8,468 529.3 1.89 112%

256 2,026 506.6 0.99 111% 256 2,115 528.7 7.55 113%

1024 530 529.9 3.77 112% 1024 529 529.2 30.23 113%

Sequential Write

R5 4+1 x2


Sequential Write

R5 4+1 x2




RT [msec]

SAS/SSD IOPS

0.5 17,965 8.8 0.11 96.4% 0.5 76,372 37.3 0.21 98.0%

4 16,153 63.1 0.12 96.5% 4 61,942 242.0 0.26 99.5%

16 11,669 182.3 0.17 96.8% 16 28,970 452.7 0.55 85.5%

64 5,752 359.5 0.35 97.7% 64 7,587 474.2 2.10 89.6%

256 1,819 454.9 1.10 89.8% 256 1,873 468.2 8.38 88.5%

1024 474 474.0 4.22 89.5% 1024 468 467.7 34.20 88.4%


15 Drives

Sequential Read

R5 4+1 x3


Sequential Read

R5 4+1 x3




RT [msec]

SSD/SAS IOPS

0.5 36,057 17.6 0.08 98% 0.5 189,013 92.3 0.13 104%

4 33,238 129.8 0.09 100% 4 149,562 584.2 0.16 109%

16 23,063 360.4 0.13 100% 16 58,222 909.7 0.41 102%

64 11,409 713.1 0.26 103% 64 16,856 1,053.5 1.42 111%

256 3,643 910.7 0.82 105% 256 4,568 1,142.0 5.25 120%

1024 1,010 1,010.1 2.97 107% 1024 1,152 1,152.5 20.82 121%

Sequential Read

R5 4+1 x3


Sequential Read

R5 4+1 x3




RT [msec]

SAS/SSD IOPS

0.5 36,911 18.0 0.08 102.4% 0.5 182,233 89.0 0.13 96.4%

4 33,280 130.0 0.09 100.1% 4 137,689 537.8 0.17 92.1%

16 23,009 359.5 0.13 99.8% 16 57,147 892.9 0.42 98.2%

64 11,069 691.8 0.27 97.0% 64 15,206 950.4 1.58 90.2%

256 3,472 868.0 0.86 95.3% 256 3,808 951.9 6.30 83.4%

1024 940 940.3 3.19 93.1% 1024 952 951.8 25.21 82.6%

Sequential Write

R5 4+1 x3


Sequential Write

R5 4+1 x3




RT [msec]

SSD/SAS IOPS

0.5 26,409 12.9 0.11 99% 0.5 113,652 55.5 0.21 99%

4 24,276 94.8 0.12 101% 4 90,075 351.9 0.27 101%

16 17,075 266.8 0.18 100% 16 48,347 755.4 0.50 114%

64 8,529 533.0 0.35 101% 64 12,125 757.8 1.97 110%

256 2,867 716.7 1.05 108% 256 3,019 754.8 7.90 110%

1024 757 756.5 3.96 109% 1024 756 756.2 31.74 110%

Sequential Write

R5 4+1 x3


Sequential Write

R5 4+1 x3




RT [msec]

SAS/SSD IOPS

0.5 26,613 13.0 0.11 100.8% 0.5 114,751 56.0 0.21 101.0%

4 24,145 94.3 0.12 99.5% 4 88,794 346.8 0.27 98.6%

16 17,005 265.7 0.18 99.6% 16 42,588 665.4 0.56 88.1%

64 8,477 529.8 0.35 99.4% 64 11,041 690.1 2.16 91.1%

256 2,661 665.2 1.13 92.8% 256 2,736 683.9 8.71 90.6%

1024 694 693.8 4.32 91.7% 1024 686 686.3 34.96 90.8%


20 Drives

Sequential Read

R5 4+1 x4


Sequential Read

R5 4+1 x4




RT [msec]

SSD/SAS IOPS

0.5 49,664 24.2 0.08 95% 0.5 243,842 119.1 0.13 116%

4 43,282 169.1 0.09 96% 4 195,664 764.3 0.16 110%

16 31,090 485.8 0.13 98% 16 77,671 1,213.6 0.41 102%

64 15,062 941.4 0.26 102% 64 22,479 1,404.9 1.42 110%

256 4,898 1,224.6 0.82 105% 256 6,094 1,523.5 5.25 120%

1024 1,337 1,336.9 2.99 106% 1024 1,536 1,535.9 20.83 120%

Sequential Read

R5 4+1 x4


Sequential Read

R5 4+1 x4




RT [msec]

SAS/SSD IOPS

0.5 52,399 25.6 0.08 105.5% 0.5 211,105 103.1 0.15 86.6%

4 45,233 176.7 0.09 104.5% 4 178,339 696.6 0.18 91.1%

16 31,769 496.4 0.13 102.2% 16 76,141 1,189.7 0.42 98.0%

64 14,758 922.4 0.27 98.0% 64 20,363 1,272.7 1.57 90.6%

256 4,686 1,171.6 0.85 95.7% 256 5,096 1,273.9 6.28 83.6%

1024 1,259 1,259.0 3.18 94.2% 1024 1,276 1,276.1 25.08 83.1%

Sequential Write

R5 4+1 x4


Sequential Write

R5 4+1 x4




RT [msec]

SSD/SAS IOPS

0.5 35,735 17.4 0.11 102% 0.5 147,353 71.9 0.22 100%

4 31,769 124.1 0.13 102% 4 116,121 453.6 0.27 101%

16 22,720 355.0 0.18 101% 16 62,085 970.1 0.51 112%

64 11,124 695.3 0.36 101% 64 15,512 969.5 2.06 108%

256 3,727 931.7 1.07 108% 256 3,863 965.9 8.23 109%

1024 968 968.2 4.13 107% 1024 969 969.1 33.02 108%

Sequential Write

R5 4+1 x4


Sequential Write

R5 4+1 x4




RT [msec]

SAS/SSD IOPS

0.5 35,146 17.2 0.11 98.4% 0.5 146,653 71.6 0.22 99.5%

4 31,126 121.6 0.13 98.0% 4 115,288 450.3 0.28 99.3%

16 22,507 351.7 0.18 99.1% 16 55,581 868.4 0.58 89.5%

64 11,013 688.3 0.36 99.0% 64 14,380 898.7 2.22 92.7%

256 3,463 865.8 1.15 92.9% 256 3,559 889.7 8.91 92.1%

1024 904 904.1 4.42 93.4% 1024 895 895.1 35.74 92.4%


APPENDIX D. Test-3 Full Results Random Mixed Workloads All of the detailed test results are shown below in these four sets of tables (by block sizes, using 2KB, 4KB, 8KB, and 16KB).

2KB Block

Random 2KB 5 SSD 5 SAS 10 SSD 10 SAS

R5 4d+1p 8 Threads 8 threads 16 Threads 16 Threads

Read % IOPS RT [msec] IOPS RT [msec] IOPS RT [msec] IOPS RT [msec]

100 18,776 0.4 1,323 6.0 37,670 0.4 2,649 6.0

75 8,214 1.0 1,000 8.0 16,504 1.0 2,001 8.0

50 7,136 1.1 907 8.8 14,318 1.1 1,816 8.8

25 7,191 1.1 874 9.2 14,483 1.1 1,759 9.1

0 7,277 1.1 702 11.4 14,600 1.1 1,410 11.3


R5 4d+1p 24 Threads 24 Threads 32 Threads 32 Threads


100 55,569 0.4 3,975 6.0 73,470 0.4 5,293 6.0

75 24,515 1.0 2,996 8.0 32,349 1.0 3,985 8.0

50 21,115 1.1 2,728 8.8 27,675 1.2 3,636 8.8

25 20,810 1.1 2,646 9.1 26,996 1.2 3,538 9.0

0 20,616 1.2 2,114 11.4 26,628 1.2 2,818 11.4

4KB Block




100 14,510 0.5 1,362 5.9 29,143 0.5 2,728 5.9

75 7,670 1.0 1,014 7.9 15,397 1.0 2,021 7.9

50 6,777 1.2 915 8.7 13,655 1.2 1,833 8.7

25 6,860 1.2 887 9.0 13,826 1.2 1,794 8.9

0 6,786 1.2 708 11.3 13,681 1.2 1,421 11.3




100 43,329 0.5 4,098 5.9 57,539 0.6 5,451 5.9

75 22,901 1.0 3,036 7.9 30,250 1.1 4,038 7.9

50 20,118 1.2 2,736 8.8 26,512 1.2 3,648 8.8

25 19,988 1.2 2,680 9.0 26,096 1.2 3,572 9.0

0 19,635 1.2 2,131 11.3 25,486 1.3 2,842 11.3


8KB Block




100 9,628 0.8 1,397 5.7 19,358 0.8 2,791 5.7

75 6,447 1.2 1,025 7.8 12,957 1.2 2,047 7.8

50 5,936 1.3 914 8.8 11,906 1.3 1,820 8.8

25 6,007 1.3 892 9.0 12,103 1.3 1,795 8.9

0 5,535 1.4 714 11.2 11,163 1.4 1,437 11.1




100 28,929 0.8 4,184 5.7 38,519 0.8 5,581 5.7

75 19,377 1.2 3,071 7.8 25,614 1.2 4,081 7.8

50 17,712 1.4 2,725 8.8 23,446 1.4 3,637 8.8

25 17,837 1.3 2,696 8.9 23,557 1.4 3,589 8.9

0 16,620 1.4 2,696 11.2 22,062 1.4 2,865 11.2

16KB Block




100 6,679 1.2 1,338 6.0 13,372 1.2 2,677 6.0

75 4,298 1.9 991 8.1 8,611 1.9 1,982 8.1

50 3,910 2.0 881 9.1 7,887 2.0 1,758 9.1

25 4,139 1.9 912 8.8 8,317 1.9 1,830 8.7

0 4,028 2.0 746 10.7 8,114 2.0 1,494 10.7




100 20,038 1.2 4,005 6.0 26,672 1.2 5,334 6.0

75 12,905 1.9 2,979 8.1 17,205 1.9 3,956 8.1

50 11,766 2.0 2,639 9.1 15,643 2.0 3,517 9.1

25 12,386 1.9 2,744 8.7 16,458 1.9 3,653 8.8

0 12,098 2.0 2,240 10.7 16,130 2.0 2,986 10.7


APPENDIX E. Test-4 Full Results Sequential Workloads Using Default 256KB RAID Chunk These tests used mixed sequential workloads and block sizes of 64KB, 128KB, 256KB, 512KB, and 1024KB with the default RAID formatting chunk size of 256KB. Tests were run on 5, 10, 15 and 20 drives using 1, 2, 3, or 4 LUNs. Both SSD and SAS drive results are listed.

64KB Block

Sequential 64KB 5 SSD 5 SAS 10 SSD 10 SAS

R5 4d+1p 1 Thread 1 Thread 2 Threads 2 Threads

Read % MB/sec RT [msec] MB/sec RT [msec] MB/sec RT [msec] MB/sec RT [msec]

100 249.3 0.2 254.7 0.2 493.2 0.3 481.4 0.3

75 161.6 0.4 91.0 0.7 320.8 0.4 212.7 0.6

50 127.4 0.5 95.7 0.7 255.1 0.5 190.1 0.7

25 113.7 0.5 90.9 0.7 228.9 0.5 185.9 0.7

0 186.6 0.3 189.7 0.3 374.1 0.3 366.2 0.3




100 718.4 0.3 698.2 0.3 971.9 0.3 946.2 0.3

75 477.8 0.4 335.8 0.6 626.0 0.4 421.1 0.6

50 378.4 0.5 284.8 0.7 503.9 0.5 381.6 0.7

25 338.6 0.6 274.1 0.7 446.7 0.6 361.9 0.7

0 539.9 0.3 527.5 0.4 714.9 0.3 697.4 0.4

128KB Block




100 273.2 0.5 275.6 0.5 546.4 0.5 566.8 0.4

75 171.0 0.7 146.9 0.8 342.1 0.7 288.2 0.9

50 111.2 1.2 109.7 1.2 210.8 1.2 223.2 1.1

25 57.3 2.5 48.9 3.0 93.5 3.0 127.9 2.1

0 221.2 0.6 215.9 0.6 441.7 0.6 438.8 0.6




100 787.1 0.5 803.1 0.5 1055.9 0.5 1061.3 0.5

75 491.4 0.8 423.0 0.9 652.7 0.8 565.4 0.9

50 325.0 1.2 322.6 1.2 399.0 1.3 426.6 1.2

25 173.8 2.3 179.6 2.1 183.9 2.8 212.0 2.5

0 635.6 0.6 625.0 0.6 823.6 0.6 807.8 0.6


256KB Block




100 313.4 0.8 319.6 0.8 626.7 0.8 604.5 0.8

75 65.3 3.9 58.4 4.4 128.9 4.0 151.9 3.4

50 32.7 7.8 31.9 7.9 68.8 7.3 69.7 7.3

25 26.5 9.8 30.8 9.0 51.0 9.9 55.4 9.4

0 255.5 1.0 229.7 1.1 509.8 1.0 457.1 1.1




100 891.7 0.8 865.6 0.9 1218.8 0.8 1179.4 0.8

75 180.2 4.2 187.0 4.1 241.0 4.2 238.7 4.2

50 91.5 8.2 93.5 8.1 117.9 8.5 119.8 8.4

25 69.8 10.8 74.9 10.3 97.6 10.4 102.6 10.0

0 716.6 1.0 665.5 1.1 938.9 1.1 866.2 1.2

512KB Block




100 328.5 1.5 315.2 1.6 657.1 1.5 642.1 1.6

75 97.7 5.2 91.1 5.6 192.9 5.2 185.0 5.5

50 51.4 10.1 50.9 9.9 106.2 9.5 101.8 10.0

25 38.7 13.0 38.9 13.3 78.7 12.9 86.8 12.0

0 263.1 1.9 242.8 2.1 524.4 1.9 477.0 2.1




100 946.9 1.6 907.9 1.6 1257.4 1.6 1210.6 1.6

75 269.4 5.6 255.7 5.9 347.7 5.8 343.8 5.9

50 149.3 10.1 140.8 10.7 189.7 10.6 183.0 11.0

25 110.3 13.6 110.1 13.7 144.2 13.9 143.7 14.0

0 747.6 2.0 684.7 2.2 960.3 2.1 887.1 2.3


1024KB Block




100 334.7 3.0 328.3 3.0 667.8 3.0 647.8 3.1

75 241.2 4.1 198.8 5.0 481.4 4.2 404.2 4.9

50 182.9 5.5 151.2 6.6 367.2 5.4 292.5 6.8

25 149.2 6.7 120.1 8.3 299.5 6.7 243.7 8.2

0 266.1 3.8 236.7 4.2 529.8 3.8 473.9 4.2




100 942.4 3.2 916.0 3.3 1285.8 3.1 1244.8 3.2

75 706.7 4.2 596.7 5.0 938.7 4.3 782.6 5.1

50 539.8 5.6 433.4 6.9 720.9 5.5 583.0 6.9

25 443.8 6.8 361.7 8.3 586.2 6.8 478.4 8.4

0 756.4 4.0 690.8 4.3 967.5 4.1 898.6 4.4

Sequential Workloads Using Optional 64KB RAID Chunk These tests used mixed sequential workloads and block sizes of 64KB, 128KB, 256KB, 512KB, and 1024KB with the optional RAID formatting chunk size of 64KB. Tests were run on 5, 10, 15 and 20 drives using 1, 2, 3, or 4 LUNs. Both SSD and SAS drive results are listed.

64KB Block, 1 Thread / LUN, 5, 10, 15, 20 drives




100 251.5 0.2 245.9 0.3 504.3 0.2 467.0 0.3

75 142.7 0.4 106.3 0.6 285.4 0.4 200.2 0.6

50 120.9 0.5 79.4 0.8 243.6 0.5 163.3 0.8

25 107.3 0.6 66.0 1.0 211.1 0.6 142.9 0.9

0 196.3 0.3 200.3 0.3 394.8 0.3 392.8 0.3




100 723.8 0.3 690.4 0.3 972.9 0.3 940.0 0.3

75 420.2 0.4 305.4 0.6 566.7 0.4 400.9 0.6

50 361.9 0.5 232.0 0.8 484.1 0.5 324.9 0.8

25 319.4 0.6 206.5 0.9 412.5 0.6 281.3 0.9

0 561.1 0.3 551.0 0.3 755.5 0.3 751.2 0.3






100 286.1 0.4 281.8 0.4 569.0 0.4 521.2 0.5

75 166.5 0.7 117.2 1.1 334.8 0.7 234.0 1.1

50 136.6 0.9 82.9 1.5 265.0 0.9 167.2 1.5

25 110.0 1.1 69.4 1.8 219.5 1.1 150.0 1.7

0 239.3 0.5 248.9 0.5 473.9 0.5 434.0 0.6




100 824.5 0.5 792.0 0.5 1102.0 0.5 1059.7 0.5

75 495.1 0.8 332.9 1.1 663.2 0.8 451.3 1.1

50 385.0 1.0 254.4 1.5 526.2 0.9 326.7 1.5

25 325.4 1.2 222.7 1.7 437.6 1.1 298.7 1.7

0 674.2 0.6 651.8 0.6 887.0 0.6 829.7 0.6





100 317.9 0.8 303.6 0.8 646.5 0.8 572.9 0.9

75 197.7 1.3 129.6 1.9 399.5 1.2 262.3 1.9

50 150.5 1.7 88.1 2.8 306.1 1.6 183.9 2.7

25 122.1 2.0 69.3 3.7 247.5 2.0 151.3 3.3

0 269.1 0.9 216.1 1.2 536.2 0.9 429.3 1.2




100 908.2 0.8 839.4 0.9 1231.7 0.8 1160.4 0.9

75 590.5 1.3 379.3 2.0 789.4 1.3 525.5 1.9

50 445.7 1.7 272.2 2.8 596.1 1.7 366.8 2.7

25 362.2 2.1 237.7 3.2 486.3 2.1 299.5 3.3

0 770.5 1.0 575.4 1.3 1040.0 1.0 954.9 1.0






100 335.1 1.5 327.4 1.5 668.9 1.5 600.8 1.7

75 213.8 2.3 150.3 3.3 431.6 2.3 303.5 3.3

50 155.0 3.2 120.3 4.2 312.5 3.2 204.7 4.9

25 126.9 3.9 81.1 6.2 251.1 4.0 167.3 6.0

0 271.9 1.8 237.4 2.2 537.2 1.9 298.9 3.4




100 954.4 1.6 908.4 1.6 1282.2 1.6 1232.1 1.6

75 641.0 2.3 420.5 3.6 851.2 2.3 594.3 3.4

50 463.5 3.2 330.1 4.6 631.2 3.2 446.3 4.5

25 372.2 4.0 269.6 5.6 502.0 4.0 347.6 5.8

0 787.1 1.9 542.8 2.9 1032.0 1.9 831.8 2.4





100 335.3 3.0 325.4 3.1 673.8 3.0 647.6 3.1

75 209.8 4.8 158.7 6.3 419.6 4.8 317.5 6.3

50 146.9 6.8 95.9 10.5 295.3 6.8 193.8 10.4

25 126.9 7.9 75.1 13.4 251.4 8.0 159.7 12.6

0 270.2 3.7 206.3 5.3 536.0 3.7 420.6 4.9




100 972.9 3.1 937.1 3.2 1310.7 ‐ 1247.1 3.2

75 617.7 4.9 493.6 6.1 840.6 ‐ 630.7 6.4

50 433.2 6.9 292.6 10.3 582.9 ‐ 410.0 9.8

25 375.0 8.0 248.1 12.1 504.1 ‐ 328.3 12.2

0 815.4 3.7 547.0 5.6 1048.8 ‐ 650.8 6.2


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AMS2500 Performance Report

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Transcript of AMS2500 Performance Report