Hi ricky73
I would suggest to use vcops or some other tool, but just do it quickly and dirty:
Go to the vGuest, hit Monitor on the right, go to Advanced.
There you can choose the Chart you wanna have a look to it. Check the CPU in real time, then modify by hitting chart options.
There you can change it to the last month or even look at it for the last year. If you see that the CPU was constantly under 100% just change it to 2 vCPUs instead of 4 or from 8 to 6 whatever and then monitor it again.
Best regards,
Marco
Check my blog, and if my answere resolved the issue, please provide a feedback.
Marco Frias - VMware is my World
www.vmtn.blog