Cod4/gtaiv lag? Why? New graphics card!

[Ancell]

I have just bought a new graphics because my 8600gt broke. My cod4 didnt lag and my pc couldent play gta iv...

My new card is:
HIS HD 4670 IceQ Edition 1GB VGA DVI HDMI PCI-E Graphics Card

And system specs:

3ghz intel processor..
4gb ddr2 ram
160gb hdd
HIS HD 4670 IceQ Edition 1GB
700w psu
xp service pack 3

My cod4 gets 125 fps... then it drops to like 4-20 fps for 2 seconds sometimes then after 5 mins in game it stops..or other times I get lags... It on low resolution 1024 x 800 think it is... The card should also run GTAIV... Its on youtube my card playing GTA IV on loads of people pc's with low cpu's... I thought my pc speds shud at least run it on everything low.. My 8600gt just about run it on low better then thid card so ? I aint checked for latest drivers yet so maybe that could be resason..

But How do I stop cod4 lag... Even If my fps is always above 100-125 sometimes it just drops.. People told me its punkbuster but surely it dont drop it to like 4 fps at times or 40..

Please Help!

I also get this error now:

UAA HD Bus driver is missing and needs installation disk. I aint got windows **** at moment. I think I found a fix on google tho. I reinstalled sound drivers but stil getting it.. Hopefully the thing I read mite work..

Any help appreciated..

 

[Ancell]

Someone told me it could be bottle necking whats that ?

 

[Ancell]

Ok I worked bottle necking out xD

Would there be a big difference with a dual core 2.4ghz for example rather than my intel pentium 3ghz.

 

[Ancell]

Thread closed. Buying new cpu so dont worry about this..