Posted on Thursday, October 19, 2006 11:26 AM
I remember this issue when I had a mighty Rock laptop with a desktop processor and Hyper Threading. Virtual Server can only allocate a single CPU to a guest. Therefore when the guest is CPU bound it is only really getting 50% of the host machine. This is far from ideal! This is made worse by the fact that the absolute clock speed of dual core machines is less than single core machines, which means it is 50% of less.
The mitigation is that when running one guest Virtual Machine the host has a full CPU to service the host, allowing the host to remain very responsive to other activities. The chances are more and more likely now that you will in fact be running more than one VM and therefore all cores will get utilised, but it still doesn't allow one very CPU hungry VM to consume all system CPU resources whilst the others are idle. This can be the case if you have a VM with all the dev tools on and another with all the server products on. When you run a build, the server VM will be mostly idle whilst the dev VM will be very CPU hungry and not able to get as much as it can.
What's the answer - VMWare?...