My VM host is ESX3, 8 CPU x 3.00GHZ, Hyper threading Active. Its currently host around 20 VM's with no performance issues.
I have just introduced a new guest Windows 2003 server standard. We have used our defaults of 1Gb of ram and 1 CPU (no reservations and no limits). This guest is running a multi threaded application called FloSuite. Whenever our users perform "tasks" on this server the guest CPU is maxing out at 100%. I have tried adding another virtual CPU to this server and it improved performance but not by much. I note that memory is not an issue.
I have read many differing articles about using multiple virtual CPU's in a guest and I am confused as to what the best practise would be to improve CPU performance in this instance. Sorry for being vague but should I throw more virtual CPU's at the server? Guidance on how to increase the guest performance would be appreciated.