Higher than normal cpu use

Getting really high CPU spikes around the 80 even 100% with wavetable synths, especially Serum..other users dont have a problem.

It seems to jump around during play back and doesn't really stick within a set range, it goes from 30 to 100 back to 50%, its all over the place.

I have optimized this computer so I cant figure it out. It should be more than capable at handling these synths.

Any suggestions?