Hi, I'm hoping for some help with an "upgrade." I'm not a competitive Quaker but I'm posting here because you guys understand that game engine and its needs better than the general public on hardware forums.

So, I have an old desktop with a CRT running XP Pro. I'd like to keep that OS, not get newer Windows, nor GNU/Linux (only using the box for gaming, will be offline otherwise). I only want to play idTech3-based games like Q3, RTCW, SOF2, ET, COD1, and other games from that era, plus some older ones, at 125 fps no matter how much action. Over time various components on my old box have died, so right now it's hobbling along on a P4 and FX5600 which drop to 30 fps at times.

I just want a good-enough "new" CPU, mobo, RAM, PSU, GPU. I don't need anything else. My absolute max budget is US $200.

I know the latest chipset supported by XP is Intel 7, but something older is fine if necessary to fit my budget, as long as it fills my needs.

I don't care about future-proofing for newer games, or running resolutions above 1024x768.

About 10 years ago I got plenty of performance from an AMD Opteron and GeForce 6800 Ultra, so anything equal to or better than those should suffice. I just don't know where to start because I haven't looked at hardware in a decade.

Thanks!