video lags when game starts

[Terminateall]

Hi there,

i am having an issue with pcsx2 0.9.6, i sm trying to play a game (samurai showdown) initial part comes fine (the intoduction section) but, when the actual game starts the vide starts lagging and sound also. my CPU usage bounces upto 100 %
plugins:- cdvdGigaherz.dll, CDVDiso.dll, CDVDnull.dll, cdvdPeops.dll.

System Configuration:-
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intel core to duo E7300 2.67 Ghz
nvidia 9600 video card
4 GB ram
MSI Motherboard

Can anyone Help me with this?
Any Suggestions are appreciated.

Thanks & Regards.