We have a Hyper-V cluster with Windows Server 2012 (it had been Server 2008 R2 before with the same issue). The hosts have 4 12-core Opteron CPUs and 320 GB RAM.
Now, the perceived performance on the virtual machines is quite poor. This is, certain actions in certain applications take way longer than on a physical machine (while other actions in other applications are working fine).
I ran several benchmarks in multiple virtual and physical machines, but could not find a notable difference. CPU, disk, cache performance are perfect. RAM performance is rather poor compared to Intel systems (ca. 1900 MB/s while my i5 desktop shows 7500 MB/s), but I found that it's similarly poor on physical AMD-based servers (around 2100 MB/s, so it seems to be related to the CPUs or chipsets). (These physical AMD-based servers perform well, so the issue does not seem to be related to that RAM performance.)
Does anyone have an idea what could cause this? Are there any other things I could test or performance counters I could watch?
- Edited by svhelden Tuesday, April 02, 2013 5:14 AM