E1705 fps help needed in Half-Life 2

[vesuvius333]

I have a E1705 Dell laptop. Dual core 2 gigs ram, 7900gs 100gig 7200rpm hard drive. I used to be able to play Half-Life 2 deathmatch at 1280 X 700 with most of the options on high a couple of months ago. Now at first I get fps in the range of 60-150 for a good 30 minutes, then as I continue to play the fps drops severely. It drops all the way down to 9 and consistently stays in the 20's. This occurs even with the lowest settings unless I look at the sky or the ground. If I leave the game idle for around 20-30 minutes my fps goes up steadily until it hits the highs I had obtained when I had first started playing. This is in HL2 deathmatch no matter the map that is being played. I have reformatted my computer and this problem still persists. Shouldn't I be able to run HL2 deathmatch at 1280 X 700 with 30 fps or above? This is a refurbished dell btw. Temps are good rarely hitting 85C. I even put the fans on high for a bit to see if it indeed was a temp problem, but that had no effect on my fps. Any help is much appreciated.

 

[JustaGeek]

Open it and clean it thoroughly from all the dust, paying special attention to the heatsinks.

Get yourself Laptop Cooler, to further reduce the heat.

Your laptop and/or Video Card is overheating.

 

[Throckmorton]

This is not really related but I think you should be able to run HL2 at native res with that video card.

 

[vesuvius333]

Thanks for the replies. I will definitely open up the laptop and take out all the gunk/dust that has accumilated. I was just wondering though my temps have been pretty much the same since I received the laptop. When I am checking the temps using I8kfanGUI it reads at 62C when idle. Is that hot?