How We Test Samsung's 845DC EVO SSD
|Processor||Intel Core i7-3960X (Sandy Bridge-E), 32 nm, 3.3 GHz, LGA 2011, 15 MB Shared L3, Turbo Boost Enabled|
|Motherboard||Intel DX79SI, X79 Express|
|Memory||G.Skill Ripjaws Z-Series (4 x 4 GB) DDR3-1600 @ DDR3-1600, 1.5 V|
|System Drive||Intel SSD 320 160 GB SATA 3Gb/s|
|Host Bus Adapter||LSI SAS 9300-8e|
|Tested Drives||Samsung 845DC EVO 960 GB|
|Comparison Drives||Micron M500DC 800 GBMicron P400m 200 GBIntel SSD DC S3500 480 GBIntel SSD DC S3700 800 GBSanDisk Optimus Eco 400 GBSeagate 600 Pro 200 GB|
|Graphics||AMD FirePro V4800 1 GB|
|Power Supply||OCZ ModXStream Pro 700 W|
|System Software and Drivers|
|Operating System||Windows 7 x64 Ultimate|
|Driver||Graphics: AMD 8.883|
|Iometer v1.1.0||Four Workers, 4 KB Random: LBA=Full, Span Varying Queue Depths|
|ATTO||v2.4.7, 2 GB, QD=4|
|Custom||C++, 8 MB Sequential, QD=4|
|Enterprise Testing: Iometer Workloads||Read||Write||512 Bytes||1 KB||2 KB||4 KB||8 KB||16 KB||32 KB||64 KB||128 KB||512 KB|
The Storage Networking Industry Association (SNIA), a working group made up of SSD, flash, and controller vendors, has a testing procedure that attempts to control as many of the variables inherent to SSDs as possible. SNIA’s Solid State Storage Performance Test Specification (SSS PTS) is a great resource for enterprise SSD testing. The procedure does not define what tests should be run, but rather the way in which they are run. This workflow is broken down into four parts:
- Purge: Purging puts the drive at a known starting point. For SSDs, this normally means Secure Erase.
- Workload-Independent Preconditioning: A prescribed workload that is unrelated to the test workload.
- Workload-Based Preconditioning: The actual test workload (4 KB random, 128 KB sequential, and so on), which pushes the drive towards a steady state.
- Steady State: The point at which the drive’s performance is no longer changing for the variable being tracked.
These steps are critical when testing SSDs. It’s incredibly easy to not fully condition the drive and still observe out-of-box behavior, which may lead one to think that it’s steady-state. These steps are also important when going between random and sequential writes.
For all performance tests in this review, the SSS PTS was followed to ensure accurate and repeatable results.
All tests employ random data, when available. Samsung's 845DC EVO does not perform any data compression prior to writing, so there is no difference in performance-based data patterns.
For comparison purposes, we evaluated the 845DC EVO against similar products from Micron, Intel, SanDisk, and Seagate.