I am also working on this, it seems there are a few programs that cna run on VPS that allow it to use all CPU, and while SWSoft says they are working to fix it, they have not gotten a patch to fix it yet.
I am looking at it on KVM now, and trying to find what task is using all the cpu(yes all 4 of them), but it also being very slow for me. However I must know what task it is in order to report to swsoft, and resolve the issue, and work to prevent.