Just wanted to bring some closure to this thread. I picked up a new 180W FSP mATX power supply for this box. It has 10A on the +12V rail (vs. 2A for the stock PS!) and around 16A on the +5V and +3.3V rails. I was able to use a Voodoo3 3000 with no problem. It uses 64W during the Quake II timedemo. Remember that the old setup with the Banshee used 62W for the same timedemo, but this new PS is probably more efficient. Turns out the issue was the anemic stock power supply!

An update to the update! Turns out that Voodoo3 3000 card is the ONLY AGP card I have (besides the Banshee) that works with the new PS. I even have a second Voodoo3 3000 AGP that does NOT work (beeps during posting process like the other cards). I'm guessing that some revisions of the Voodoo3 3000 draw less power than others? TNT2 Ultra and ATI Rage 128 Pro both do not post. I probably would have kept the Voodoo3 in there anyway, but it would have been nice to run some benchmarks.

I also have a Voodoo3 2000 PCI that does work with the new PS. In case you're wondering, the AGP card does 76.7 fps at 1024x768 in Quake II, while the PCI does 70.0 fps.

I use these for my test benches:

I mostly got them because the price difference between 350W and this 500W are tiny. Haven't any issues powering up anything so far 😀

There used to be a utility to help calculate what PSU you'd need, based on the components you picked. I'll see if I can dig it up, to see if it can help.

Worst case, if I get bored, i'll go trolling for datasheets. Those will definitely list power draw for those old cards.

<Marvin>Go down the right back alley of the internet, and you can find anything.</Marvin>