Perfromace drop after extended play

I am playing Fallout 3 on my laptop (sig), with these settings:
1280x800
AA: off, AF:x8
VSync: off
Shadows: off
HDR
Texture quality high
all else similar to medium settings

I get very comfortable FPS and no stuttering during the first 1.5 - 2 hours of playing, but then I get a lot of stuttering on outside locations and FPS drops...

I don't really understand how gaming works (in terms of GPU-HDD-RAM usage), so what could be causing this? possible solutions?

thanks!

 

Probably a forced GPU downclock due to high laptop temps? o.o Try monitoring the temperatures. I've heard of the 8600M GT GPUs getting extremely high temps of up to 90 degrees

 

^ I haven't noticed any excessive heating, but I will monitor them tonight.

 

Well, at least my 9500M GS seems to randomly downclock itself now and then. Not temperature related, mind you. Heard some other guy having the same problem, so could be that.

 

Yeah, I had the issue with the 9500m GS as well. And the card won't downclock for 90 degrees. It would have to get higher than that. I thought I had the issue figured out but I had it pop up again last night with Empire Total War. The card is clocking down to non performance 2d (goes from 500 core to 183) and all the other clocks drop as well. Some people said alt-tabing out of Fallout was helping but I can't seem to get this to work. It is ultimatley a driver issue but no one seems to to know why (talked to Nvidia, Microsoft, and ASUS). The only "fix" I have heard is to force the card to go to 3d clocks at all times, which may have an adverse affect on the hardware in the long run.

 

I don't think this is your problem, but just incase. Fallout 3 ran great on my computer until every now and then it would lag like terribly. It felt as if its FPS were like 2-5, but the FPS counter still said 40-50. I dunno what its caused by but when that happened I just alt tabb'd out and alt tabb'd back in and it was gone. Some bug or something. Try that next time, if thats not the problem. Then it could be down clocking.

 

if you meant playing on the battery without plugin to a power outlet.
on battery only, computer will downclocke itself to 1/4 of peformance of plugin.

 

Temps never go over 70 °C, even after 3 hours of gamplay.

However now I turned AA and AF off, reduced all LOD distances to halfway and disabled most water effects, and its better. I get constant 40-42 FPS, and after a while they occasionally drop to 30-35, which is still ok. The only times it goes down to <20 FPS for a few seconds is if I turn my character around 180° very suddenly...

I meant outside within the game world. Inside houses and such works fine (there is less things to draw), and outside on the wastelands, FPS go down. I guess thats normal.

I tried Alt-tabbing a couple of times (for other reasons) and the game crashed...

 

When this happens, check your background processes, maybe you have something going on at this time, as a coincidence, which is causing the slowdown.

 

Try updating drivers.
If you never go above 70C, then you're ok!

Try:
- Drivers
- Disk defrag

Might help

Then again, like it was mentioned, might be a background process, antivirus or something doing its routine checkup?

 

I am on 176.44 drivers... downloading 179.48 right now.

Now that I think, I have never defrag'd once since I got my laptop!... will do it also.

I don't think its antivirus, I have nothing scheduled and I disable Avira Guard for gaming.

Thanks for all the replies!