Why is my fps drop when after gaming for 10 minutes?

[airplanegeek]

I play World of Tanks at around 60 fps but after like 10 minutes the fps drops to like 20 and makes it unbearable. Sometimes the fps will go back to 60 after another 10 minutes. The fps drop only started happening recently after i restored my computer from a CD. I am on a Acer aspire TimelineX 5830TG.
i5-2430M
2GB GT 540M Overclocked
4 GB DDR3 RAM (PC3-10700 667Mhz? This is what CPU-Z says but it doesn't make sense)
750 GB 5400rpm HDD

 

[sligy]

I had the same problem with my computer but it was a problem of the pc getting heated too much.. Make sure the vent isn't blocked!

 

[airplanegeek]

I had coretemp running cpu temp was around 86 the whole time but ill still look into it

 

[Sunius]

Check temperatures and report back.

 

[airplanegeek]

yeah so it is hovering around 85 C

 

[airplanegeek]

Best answer selected by airplanegeek.