Massive FPS drop downs. Need a solution?!

Hi. I am experiencing a serious problem. Has anyone of you encountered a MASSIVE FPS DROP DOWNS in certain games? I tried to play MW3 but couldn`t. I tried left 4 dead 2 but I couldnt play. There were about 70/80 fps and suddenly it was droping to 20. Even if there was no massive movement on the screen. Even when I stood in front of the wall. My gpu is OCed 720/1800/900. On the other hand I played FlatOUT 2 at highest details and even AA turned on and everything was OK. Any ideas?

 

Check out the graphics card and CPU temps...

 

The problem may be a drop out of frame rates from the memory. Try un overclocking the video card and see if the issues persist................

 

SO. I undervolted GPU do 1.09, I downclocked to 600/800/1500. But it didn`t help. There is the same problem. When I start mission in Left 4 dead 2 I have 60 fps but when I play further it drops down after minute or two. Now I am defragmenting the partition. If it doesnt help then I give up and play games from 80/90s on my 7805u!!!!

 

Are the temps OK for both CPU and GPU?

It may be throttling.

 

so you are suggesting that it changes/lowers the clocks due to temps???

EDIT
I defragmented the drive and it helped in some way!!!

 

It's possible that it's overheating. Monitor temps while gaming to make sure it's not that.

 

I checked temps. Its about 80C on gpu.

 

That's OK but CPU temp should be checked too.

 

Here is the link to video. Look at upper left corner.


As you see I am not moving. There is some movement. Howeveer not too rapid.


EDIT:
Temps GPU/CPU are acceptable.

There is some HDD lag. However 9800 GTS has 1GB or 256bit VRAM.
I have 4gb of ram.

The res was 1366x768.
AA off
highest details.

 

this is a screennshot of MSI afterburner
Look at GPUs behaviour.

 

once you have confirmed the GPU is not declocking check for CPU and TSZx temps as these can cause frame rates to drop as well from declocking the CPU...............