Maximum CPU usage?

[Pmarsha1]

Hi,

I have a 4 node cluster running on HP BL685c blades each with 4 dual-core AMD Opteron 2.612GHz processors.

What is the maximum CPU resource that can be granted a VM with a single virtual processor?

Is it the core speed of the processor i.e 2.612GHz as I have a VM that is showing 100% CPU usage yet my hosts are hardly loaded.

i.e. It seems that the machine can only run on one core. Is this correct?

[bretti]

With a VM configured for only 1 CPU the maximum CPU resources it can use would equal the core speed of one processor, or 2.612 GHz in your case.

The scheduler will move processing around to different CPUs on the host. That may be why it looks not so busy.

[Pmarsha1]

Doe's that mean to get better performance I would have to add another vCPU?

[bretti · Accepted solution]

Well that depends on MANY different factors. But generally speaking, yes.

If you do add another vCPU make sure your OS can see both CPUs after the addition.