|Seagate Cheetah 15K.7 SAS Hard Drive ST3600057SS|
|Reviews - Featured Reviews: Storage|
|Written by Olin Coles|
|Tuesday, 27 October 2009|
Page 7 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.
Benchmark Reviews has resisted publishing Iometer results because there are hundreds of different configuration variables available, making it impossible to reproduce our tests without having our Iometer configuration file. 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. The tests are given a 50% read and 50% write distribution. Our charts show the Read and Write IOPS performance as well as I/O response time (measured in ms). Iometer was configured to test for 120 seconds, and after five tests the average is displayed in our benchmark results. The first tests included random read and write IOPS performance, where a higher I/O is preferred.
In the Random IOPS performance tests the single layer cell (SLC) OCZ Agility EX (3982/3988), Intel X25-E Extreme (3543/3548), and OCZ Vertex EX (3106/3091) outperformed all other products by a wide margin. Current-generation Solid State Drive products offer phenomenal IO performance, which is why every other product thereafter performs far beneath the above-listed products, and are not suggested for highly-intensive input/output applications.
The Western Digital VelociRaptor still fell short on IOPS performance compared with several current-generation SSDs and produced only 134/138 IO's. The Mtron MOBI 3000 performed 107 read and write IOPS, while the Seagate Cheetah 15K.6 and 15K.7 both performed around 120 IOPS each direction. The newer Mtron MOBI 3500 rendered 58 IOPS, which was worse than the older 3000 model. Next comes the average I/O response time tests...
The Iometer random IOPS average response time test results were nearly an inverse order of the IOPS performance results. It's no surprise that SLC drives perform I/O processes far better than their MLC versions, but that gap is slowly closing as controller technology improves the differences and enhances cache buffer space. The Read/Write IOPS performance for the 64GB OCZ Agility-EX SLC SSD was 0.19/0.06 ms, with the Intel X25-E Extreme SSD measuring 0.22/0.06 ms, while the OCZ Vertex EX (firmware 1.20) achieved 0.26/0.06 ms. Both of these premium MLC products share a dramatic lead ahead of the other SSDs tested. These times were collectively the best available, as each product measured hereafter performed much slower.
The Western Digital VelociRaptor did very well compared against SSD products, producing 6.59/0.82ms. The Mtron MOBI 3000 offered a fast 0.42ms read response time, but suffered a slower 8.97ms write response. The opposite was true for the Seagate 15K Cheetah's. The 15K.7 rendered reads at 8.11ms and 0.30ms writes, while the oder 15K.6 scored a 7.90ms read and 0.37 write. Mtron's newer MOBI 3500 offered great read response times at 0.19ms, but suffered poor write responses at 17.19ms.
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.