Well, let me see (grabs his copy of Doom 3):
* English version of Microsoft(r) Windows(r) 2000/XP
* Pentium(r) 4 1.5 GHz or Athlon(tm) XP 1500+ processor
· 384MB RAM
· 8x Speed CD-ROM drive (1200KB/sec sustained transfer rate) and latest drivers
* 2.2GB of uncompressed free hard disk space (plus 400MB for Windows(r) swap file)
* 100% DirectX(r) 9.0b compatible 16-bit sound card and latest drivers
* 100% Windows(r) 2000/XP compatible mouse, keyboard and latest drivers
· 3D hardware Accelerator Card Required - 100% DirectX(r) 9.0b compatible 64MB Hardware Accelerated video card and the latest drivers.
o ATI(r) Radeon 8500
o ATI(r) Radeon 9000
o ATI(r) Radeon 9200
o ATI(r) Radeon 9500
o ATI(r) Radeon 9600
o ATI(r) Radeon 9700
o ATI(r) Radeon 9800
o All Nvidia(r) GeForce 3/Ti series
o All Nvidia(r) GeForce 4MX series
o All Nvidia(r) GeForce 4/Ti series
o All Nvidia(r) GeForce FX series
o Nvidia(r) GeForce 6800 series
This is copied straight from the readme.txt file in the CD, and I can tell you it's really nuts to try and run Doom 3 like this. I had an Athlon XP 2000+, 512MB RAM, GeForce 3 Ti 200 64MB AGP, SB Live! Value and Windows 2000 SP4; the result wasn't pretty at all - blurry, bad level lighting, slow-motion monster attacks, random missing textures, low frame rate (single digits during intense fighting). Even a Pentium 4 2.4Ghz Northwood, GeForce 6600 256MB AGP, 2GB DDR2-333 RAM and Windows XP SP3 couldn't run it decently - FPS would drop like a stone in large levels and during battles with lots of gunfire. It wasn't until I got my current Core i5 rig that Doom 3 finally ran smoothly and without any problems/issues.