I'm having a serious problem running Q3A on an old laptop. It's a Fujitsu Siemens Lifebook C Series, has 700ish mb ram, and a shitty 32 MB S3 SavageProDDR Integrated video card.
As we all know, with the right settings, Q3A can still be playable. The laptop is my friends', he came to me yesterday asking for a fresh windows reinstall.

We did reinstall Windows XP + all the drivers, and Quake 3 Arena.

This was the first time Quake running on the machine. I've written a new cfg for it, (picmip 16, subdiv 80, gl_nearest, etc.) and it boosted up to 80 fps. All was nice, we cheered, but then, after a while (a minute or so) the fps started dropping from 80 to 60, 60 to 40, and there were times when it was around 9-10.

I don't know what the problem is, I only have guesses. It's not XP's automatic update, no programs running in the background. I guess it has something to do with the laptop's battery maybe? It's an old piece of shit, and heats like hell. You can't even turn on the laptop without plugging the charger in, because the battery is so bad. I really don't know. Maybe the heat causes the fps to drop?

Please help me if you can :)

Edit: We've done what we could.

We threw the battery away. We tweaked the cfg. We used speed dll-s. We uninstalled the antivirus. On pro-q3dm6, now he has from 50-to 110 fps. Thank you all! If you happen to know any other fps raising techniques, feel free to post it.