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). There is currently a new version of Iometer in beta form, which adds several new test dimensions for SSDs.
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.
All of our SSD tests used Iometer 1.1.0 (build 08-Nov-2010) by Intel Corporation to measure IOPS performance. Iometer is configured to use 32 outstanding I/O’s per target and random 50/50 read/write distribution configuration: 4KB 100 Random 50-50 Read and Write.icf. The chart below illustrates combined random read and write IOPS over a 120-second Iometer test phase, where highest I/O total is preferred:
The Samsung SSD 850 PRO produced our all-time best recorded score with 94,985 IOPS, leaving the OCZ Vector 150 (88,299 IOPS) and Vector 450 (87,323) SSDs that previously delivered the best combined IOPS performance fell nearly 6000 IOPS behind the new leader. OCZ’s Vertex 4 (83,494) and Vertex 3 Max IOPS Edition (83,117) trail behind with notable scores, before the Intel 520 SSD (80,433) and Intel 335 (80,015).
After the top-performing storage products, IOPS performance results quickly taper off. It should be noted that nearly all modern SSDs deliver I/O far beyond the needs of multi-tasking power users and hardcore gamers, and would be ideal for workstation systems running utilizing virtual machines.
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.