|OCZ Vector Solid State Drive|
|Reviews - Featured Reviews: Storage|
|Written by Olin Coles|
|Wednesday, 09 January 2013|
Page 8 of 11
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, using a SandForce-created QD30 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:
In our Iometer tests, which are configured to use 32 outstanding I/O's per target and random 50/50 read/write distribution, SandForce SSDs generally outperform the competition when tested with this large queue depth. The OCZ Vertex 4 SSD tops our charts with an impressive combined IOPS of 83,494 - the best we've seen from any SATA-based SSD. The 240GB OCZ Vertex 3 Max IOPS Edition trails behind with 83,117 IOPS while the Intel SSD 520 Series produced 80,433 peak combined IOPS. OCZ's Vector SSD trailed behind the SandForce and Marvell-based solid state products, producing a noteworthy 60,052 combined IOPS in this test. Although not among the highest I/O marks, Vector's performers delivers operational performance far beyond the needs of multi-tasking power users and hardcore gamers, and would be ideal for systems running virtual machines.
OCZ Technology suggested an additional Iometer test using their own configuration file (4KRW-15m.icf), and Benchmark Reviews was happy to ablige. We set the sector size to 250053918, which created a 50% LBA load on the SSDs tested. Then we tested again with the default sector size of 0 for 100 LBA load. This tested write performance on the Vector SSD compared to a select few other drives available, and showed some interesting results. Although the results are too complex to graph properly in our charts, the trend showed that Vector was sucessful in producing high I/O when capacity was seriously reduced, as opposed to an empty drive. Random write performance reached 57,398 IOPS, which was nearly the same as combined IOPS performance with 100% capacity. Overall, the OCZ Vector SSD showed great promise in real-world performance scenarios, where the drive will be filled with data and only a portion of it will be writable.
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.