Modern warfare 2, lag spikes during SP?

Has anyone else been having this issue?
Basically when i first started the campaign, all my settings were on except AA and texture was at automatic at 1280x800 res. The game was more than playable, very smooth even. As i went on, everything was fine until i got to around the middle of the campaign. Basically the game will play smooth for about 30 seconds and then the fps will drop like a rock to 5-10 fps for up to 10 seconds before i hit esc and wait for it to stabalize so i don't die.
In task manager i have nothing running in the background, but my cpu use is anywhere between 25-45% during gameplay, and my physical memory registers as around 75% used.

My specs:
Core 2 duo 2.0 ghz
4 gb ram
Mobility HD 3650 512mb Vram

I mean the graphics of MW2 aren't much farther from the first one, on which i could turn up AA and still get 30+ fps, but the lag spikes still happen when i turn down shadows and some textures on MW2.
Could it be overheating? ATI doesnt have a temperature sensor on their GPU's but rmclock shows my cpu at about 60c average during gameplay.

This doesn't usually happen during other games, the only other similar thing i notice is maybe in street fighter 4 where sometimes the fps will drop for a second or so but thats only very rarely, nothing major.

 

try restarting your computer, I had the same thing happened when I came home today and a restart fixed everything.

 

I haven't had this issue in WoW (not demanding enough I guess) or Dragon Age Origins (CPU intensive) yet on MW2 I had fps dips a lot.. and yeah it's my GPU, I turned off powerplay and it helped, though my performance decreased some, didn't matter since I was already running at a lower res and turned off fx.

 

How do you turn off powerplay?

And I haven't restarted my comp in a few days so i guess ill try it when i play again and post back here.

Edit: Figured out how to disable powerplay, but not sure if it matters? Seems to me all it does is just adjust performance settings based on battery or AC power.

 

What it did for me was not make the card downlock..so my 3dmark score dropped from 4400 to 3000 but I don't have dips in framerate anymore and can still run it at same settings I had it before @ 1366x768 @60FPS w/ low advanced settings except ragdoll/bullet holes on.

 

Mine doesn't dip, the game just STOPS, menus and everything, for a good second. Very annoying and unplayable.

 

My problem could be considered the equivalent of stopping, at times i would mash esc and nothing would happen, however it wouldnt last a second, it would be 3-10 seconds.

For me the solution was to just turn everything down except specular map and shadows, and this stopped happening.

 

Check textures.. I read some ATI cards can't do the EXTRA setting.. do you have any on that? Also something about drawWater set to "0" in the cofig file might help.

 

disable multicore rendering

 

i experience this problem i just defrag the hdd.

 

Hmmm, it seems after a few restarts of the machine, it goes away. How odd. It was worse in the in-game menus, now it's gone completely. There was no hdd activity either while playing.

 

there are no options settings for this in MW2..