Congrats on the 486 board! One question, your ATX->AT adapter, did it have two extra wires that led to no where? If so, those have to be connected to each other (or an ATX-style power switch) to tell the PSU to power on. My PSUs appear to work just having those two wired together, but I think some …

Clockspeed ain't going to help Quake3's texture thrashing (which is especially bad on 3dfx cards with less than 16MB - such as the Velocity 100). Your video card is the bottleneck, and this must change if you expect to hit 40fps with the presented gamut of 1999-2001 games. Perhaps a Geforce2MX is …

I recommend reflashing the bios. I have the same board as you (a Dell version running with a power adapter). It did not post until I did the flash recovery (via the jumper). Since then it’s been running flawlessly. I also have the 450KX motherboard that mostly worked, but would occasionally not post …