CPU Usage Higher with 4870X2

[sWiZzLe]

The last few days i have been using my onboard HD3200 fx card and while idling the cpu usage is around 3-6%.

Now i have got a new psu and have been able to connect up my 4870x2 my cpu usage is around 60-70& while idling.

Why is that?

 

[sWiZzLe]

40% is being used by the svchost.exe for DcomLaunch and PlugnPlay and i cant really disable them can i

 

[sWiZzLe]

Last night i defragmented all drives and did a full system scan with AVG.

Ive just restarted my pc, closed down everything in the system tray as well as some non essential processes are this is my cpu usage (Vista 64):



Now that i have opened firefox the cpu is now at 40%

When i try to play a game my cpu seems to be so high to start with that i dont have enough left to get a decent framerate and i get a lot of stuttering

I also installed Catalyst 8.10 after removing 8.8 with Driver Sweeper.