Quake3 is an old game so that should run at an easy 60FPS I think.

UT 2K4 should get you around 40FPS

Doom3 should get you around 5FPS.

Off course, this is all without software like 3dAnalyzer and MesaFX. (Doom3 playable on V2 SLI with specialized drivers)

With the demo of UT2K4 I get 20FPS average on my machine;

Voodoo 5 5500 AGP
Intel Pentium 4 2,26GHz
512MB PC2700 DDR-SDRAM

So I think the 40FPS is a reasonable assumption.

UT2003 ran fine with medium/normal detail on my athlon1400/voodoo5 5500agp,but UT2004 was lagging like hell.changing the resolution and details didnt help..

Voodoo 5 6000 runs better on 2003 then 2004 in my case. But as FalconFly said it mosltly depends on the architechture of the map. DM_Antalus was playable in high detail textures and 1024x768 though.

I dont think it was 40 frames per second or more but yeah, on a 6000 it was playable. The funniest part is that I could even play at 1600x1200 in instagib mode. Seems the weapon models and special effect are pretty demanding.

As for quake 3, in 2048x1536 I had 52 frames a second so on a 5500 you should get 60+ easy on a modest resolution. I think even 100 is not unlikely.

Doom 3 I consider unplayable. It's fun to watch for a few minutes or trying to make it run faster but playing is not recommanded  ...just like Half-Life 2.