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 isconfigured to use 32 outstanding I/O’s per target and random 50/50 read/write distributionconfiguration: 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 256GB Samsung SSD 850 PRO produced our all-time best recorded score with 94,985IOPS, which is more than twice the performance we see with the ADATA SX930. What’s embarrassing here is that the only drives below the SX930’s score are much older drives that user controllers and flash memory at least a couple of generations behind.
Nearly all modern SSDs deliver I/O far beyond the needs of multi-tasking power users and hardcore gamers; SSDs that return very high IOPS scores would be ideal for servers or workstation systems running utilizing virtual machines.
In our next section, we test linear read and write bandwidth performance and compare the speed of the ADATA SSD against several other top storage products using the AIDA64 Disk Benchmark.