I have an SSD installed in a PC. And the test tool is IOMeter. When using Centos 6.3 or Ubunut 12.04, the Random/4K/100% Read/64 Outstanding IO/s test shows about 8000 iops. But when testing in Windows 7 with the same setting. The iops is about 68000!
Even more surprising is: Random/4K/100% Write/64 Outstanding IO/s test shows 13000 iops on Centos/Ubuntu. Write is faster than read!
Can anyone tell why?
UPDATE: The SSD is Samsung 830 Series 256GB. The interface is 6Gb/s.
UPDATE: New test result. This time is much better.
Test under Centos 6.3
Raw / FS | Transfer size | Read / Write | Outstanding IO/s | IOPS raw | 4K | 100% read | 64 | ~22000 raw | 4K | 100% read | 1 | ~16k-20k fs | 4K | 100% read | 64 | ~6200 fs | 4K | 100% read | 1 | ~6400 raw | 4K | 100% write | 64 | ~29000 raw | 4K | 100% write | 1 | ~27000 fs | 4K | 100% write | 64 | ~30000 fs | 4K | 100% write | 1 | ~27000
UPDATE: Finally I found the answer: This issue is caused by IOMeter itself! It can not load the IO system at full capacity and the iops number is not correct as well! After using sysbench tool I can see the iops reach up to ~64000. Almost the same as WIN7 :)