|OWC Mercury Extreme Pro-RE SSD SSDMXRE100|
|Reviews - Featured Reviews: Storage|
|Written by Olin Coles|
|Tuesday, 01 June 2010|
Page 9 of 12
Iometer IOPS Performance
Iometer is an I/O subsystem measurement and characterization tool for single and clustered systems. Iometer does for a computer's I/O subsystem what a dynamometer does for an engine: it measures performance under a controlled load. Iometer was originally developed by the Intel Corporation and formerly known as "Galileo". Intel has discontinued work on Iometer, and has gifted it to the Open Source Development Lab (OSDL).
Iometer is both a workload generator (that is, it performs I/O operations in order to stress the system) and a measurement tool (that is, it examines and records the performance of its I/O operations and their impact on the system). It can be configured to emulate the disk or network I/O load of any program or benchmark, or can be used to generate entirely synthetic I/O loads. It can generate and measure loads on single or multiple (networked) systems.
To measure random I/O response time as well as total I/O's per second, Iometer is set to use 4KB file size chunks over a 100% random sequential distribution at a queue depth of 32 outstanding I/O's per target. The tests are given a 50% read and 50% write distribution. While this pattern may not match traditional 'server' or 'workstation' profiles, it illustrates a single point of reference relative to our product field.
The chart below illustrates combined random read and write IOPS over a 120-second Iometer test phase, where highest I/O total is preferred:
From the onset, SandForce SSDs clearly outperform the competition when tested which a larger queue depth. While G.Skill's product website displays an image of their Iometer results reaching nearly 50,118 IOPS, there's no telling what settings were used for this test. In our own Iometer tests, which use 32 outstanding I/O's per target and a random 50/50 read/write distribution, only the 'unrestricted' SandForce SSDs approach 50,000 IOPS. These SSDs demonstrate a much higher performance level due to the custom firmware they've implemented, whereas the others each use 'locked' standard-release SandForce firmware that offers consistently identical results. Benchmark Reviews discusses this topic in more detail in our SandForce SF-1200 SSD Firmware Comparison article.
In our next section, we test linear read and write bandwidth performance and compare its speed against several other top storage products using EVEREST Disk Benchmark. Benchmark Reviews feels that linear tests are excellent for rating SSDs, however HDDs are put at a disadvantage with these tests whenever capacity is high.