Hi friends!

The motherboard of my 3dfx gaming pc only have three PCI slots, and one AGP. The PCI are filled with my recently adquired Voodoo1, a S3 Virge for 2D and a PCI to USB card (Because the motherboard haven't got any USB ports).

I want to connect the pc on LAN, so I removed the S3 and plugged a Realtek network card instead. For 2D graphics I plugged a SiS 6326 AGP card (This is a shit of a card, but I want it only for 2D, so...).
With this configuration I ran 3dmark99 for testing and I get surprised when I saw 200 less points than before with the other config.
I also tested Quake 3 timedemo, and I got 16fps (I get 20 fps with the other config).

So, the Voodoo became noticeable slower with this configuration!
I also noticed that the graphics in Quake3 are much darker than before.

Then, I reverted to original configuration, with the Virge, and the performance is restored!

What's going on? Isn't supposed that the Voodoo is totally independient when on 3D mode? Why I get a reduction of performance and darker graphics? 

Regards!

The motherboard is a Superpower A586B, Socket 7 with AMD K6-2, Aladdin V chipset, 100 MHz FSB.

I haven't installed any motherboard drivers but Aladdin V AGP controller appears in Windows device manager.

AGP port seems to be working ok. I've even been using it with Voodoo 3 AGP with no problems.

I tought about it but I can't put the Voodoo in other slot because the PCI are in front of and very near to the processor's heatsink in my motherboard, and the card is too long.

I can only put the Voodoo in the slot nearer to the ISAs. In this slot, the card just passes behind the heatsink.

Well, I think these photos explain it better:

https://skydrive.live.com/redir?resid=F5054C7071DF92B9!711&authkey=!AGjDyBtetC7a...

https://skydrive.live.com/redir?resid=F5054C7071DF92B9!710&authkey=!ABruQbh0-Pce...

I have tested again with the AGP card, but I removed the network card (To discard it) and reinstalled the motherboard AGP drivers. No luck... The same performance loss.
I think it is very strange, because the AGP port should be fully independient from the PCI.

Well, I think I will give up and use the S3 Virge. But I am so courious about why an AGP card can disrupt the Voodoo PCI performance...