I am quickly trying to come to some conclusions on the performance of our ESXi 4.1 cluster and am having a little trouble getting my head around PCPU UTIL and CORE UTIL and what is a better indicator in my scenario of over utilization of CPU resources.
I have 10 servers with 2 x Quad Core processors installed with Hyperthreading enabled giving me 16 logical processors per Server. When I look at the CORE UTIL Stats it tells me that I am running at 87% Max with a 'mean' average of 52%, but the PCPU Util Stats tell me that I max at 53% and 'mean' average at 28%.
So, with Hyperthreading enabled which is the better counter to be looking at or should I consider both? From what I understand, the CORE STATS may look busy even if 2 PCPUs in the core are not both working at the same time wherby one stops getting utilized as another one starts, giving the impression that a lot more work is going on. For this reason am I better to use the PCPU Util statistics instead? A CORE stat could suggest that it is 100% busy, when it is actually only 50% could it not? Or am I totally not getting it?
I have read the superb http://communities.vmware.com/docs/DOC-9279 but would appreciate any input on the subject.
Apologies if this question has been asked before, or indeed even worse it is too stupid a question to be asked . I am new to using esxtop, and though I like the tool just need a little helping hand interpreting this bit.
Thanks in advance.