Why I have very low FPS?

Hi everyone! I only have about avg 32 fps in Crysis, but sometimes 1 or 2 fps occurs in game like 10sec. then goes back to 32 fps. I play other games never have the problem like this.

Any experts can tell me why it happens, and how can I fix it or make it better?

I don't want to play and stop and play...

my spec:
E6420
MSI 965 NEO
Kingston DDR2 800 4G
WD 10K 74GB + WD 7k4 1TB
Sapphire HD4870 x2 2GB
Corsair TX750W
Vista Ultimate 32bit
(Nothing has overclocked)

Thank you very much for your help!!!

Yes agreed. What are you doing with a cpu like this. If you want a nice one get a q9300 from intel. Or if you want a cheaper on get the q6600. But like xxcoop42xx said you need a better cpu. Once you get a better one the frams will rise a lot higher. Also this problem accurs only in crysis because its how crytech do there games. They are very demanding. You have a nice setup by the way

"Also this problem accurs only in crysis because its how crytech do there games"

Rockstar pc coders disagree.

Thank you for all your great advises!

Unfortunately, after I overclock my cpu (E6420 core 2 dual default 2.13Ghz) to 2.6Ghz, it seems getting better a little bit. I am using 26"LCD in 1920x1200 res. and ultra high settings. Should I try overclock to 2.9Ghz, and will that be better?

Forget to say I am using 8.12 driver now.

AGREE. 3.0 is the minimum for a X2 card (or sli-CF).

OC this one, you have a decent CPU cooler ?

or get a q6600 or e8400 or Q9xxx. the E8400 seem to OC like hell and is quite cheap.

As long as your FSB and multiplier permits without overheating your CPU then your good.
Though raise your FSB little by little until you reach a stable speed without crashing.

1)switch to a p45, switch to a penryn.
2)or go core-i7.

why do u need to get a second 4870x2 for a core i7 build?

Thanks for the surggests!

I know a better cpu will do a good job on my current machine, but if the lagging problem can be solve, I will be very appreciated!

Would an amd x2 anthlon 4600+ (2 cores at 2.4 ghs) be better than his intel 2.1 ghs two cores? Cause that's the budget computer I recently bought and am wondering how obselete it is. It also only has 2 gigs fo ram so far at 533 mghs and an L2 cache of 512 each.