Don't know about FS2004 but FS2002 works with my Voodoo3 2000 PCI.
Microsofts FS2004 spec says:
Microsoft® Windows® 98/Me/XP/2000
PC with 450 MHz equivalent or higher processor
128 MB of system RAM for 2000/XP, 64 MB RAM for 98/Me
1.8 GB available hard disk space
4x speed or faster CD-ROM drive
8 MB video card required
Sound card, speakers or headphones required for audio
Microsoft Mouse or compatible pointing device
56.6 Kbps or better modem for online play
8 MB video card required. Thats what is says for Train Simulator but it keeps crashing on mine. Not the train.