Hi, All
I'm testing VDI performance on ESXi 5.1. The machine is IBM X3650 M4, which has two 8 core CPU with 8 disks (15k rpm SAS) in RAID 5.
I used esxtop to collect IOPS statistics. When I looked into the data collected by esxtop for "Physical Adapter", I got average 2,000 CMD/sec and maximum 5,300 CMD/sec. The data for "Physical Device" is a little low, but nearly the same high.
Which result really surprise me. Becaues theoritically 8 disk with RAID5 (penalty is 4) can provide (50% read, 50% write):
8 * 175 * 0.5 + 8 * 175 * 0.5 * 0.25 = 875 total IOPS
Even take cache into consideration, the IOPS boundary of physical RAID disk groups shouln't normally excced 1,000.
Can anyone give me a clue why this happening and how can I get the REAL IOPS data perfomed by disks?