Video lag after a time; heat issue?

[Firebringer]

I purchased a new computer around march and I have been having a problem with video lag. Originally with the system, (P4 3.2 478 socket, 512mb ram, 80gig HDD, radeon 9800 pro) I had a geforce 4 mx 4000. When running some games, ie: Battlefield 1942 after perhaps 5 minutes of play it would start to lag... heavily! So to fix this problem I bought a Radeon 9800 Pro. Same problem, it also happened on Battlefield 2, and some other games like Rise of Nations. Strangely though, when playing Call of Duty or Warcraft three, even under some intense action everything runs fine, even Half-Life 2 and Farcry ran well! Just wondering what you think the problem might be!? Thanks in advance
-FB

 

[zephead]

512MB of ram ain't much by today's standards. try installing the latest drivers for your card and BF patches.

 

[Sharkfood]

With Battlefield2, it's definately your memory. Upgrading to 1 gig would surely help BF2 out immensely.

Even at 1 gig, BF2 will swap/page often and will start to slow down and get laggy after playing for a couple hours. 1.5-2 gigs is ideal for this game given how much a memory pig it is.