However, recently I got into gaming, and, since my career had gone from animation to a more technical field, I decided to get much more powerful consumer-level Videocard (the Quadro4 is a great card for programs like Maya, but they don't have the raw power of gaming cards). I ended up purchasing a BFG nVidia GeForce 7800GS, which was best card I could get for AGP. I installed it and booted up my machine, no problem. Unfortunately, when I tried to play one of my games (in this case World of Warcraft) the computer froze. I rebooted, same thing happened. I tried every combination of drivers for both video-card AND the Motherboard, same results. Finally, after numerous calls to BFG's support department, one of the more experienced techs told me that the video-card was incompatible with my CPU and/or chipset (not the northbridge, since there isn't one my board; it would most likely be the AGP controller chip). I ended up returning said card to Newegg for a refund.
Now I come to the point (finally!): I don't want this to happen when I build my next computer. Is there really a compatibility issue between consumer-level video-cards and Opteron processors? Or was it something that was specific to this particular motherboard? I wouldn't care about this issue if I knew I was never going to build another 3D workstation, but I can't rule that possibility out, and so I would like to resolve this issue.
PS–I know that it's not a compatibility issue with the game, since World of Warcraft and other games like Half-Life 2 run fine (although, not at the detail and frame-rate that I'd like them to) with my original configuration (the one listed above).
Your Tyan board has a limited number of recommended cards, and no current generation video cards from ATI or Nvidia. Tyan also mentions that your AGP slot is an 8X / 8X Pro 110 watt slot. I don't know if that could be the issue.
It's not the Power Supply, I have a 550W power-supply which is well within acceptable ranges for the GeForce 7800GS...I even confirmed this with BFG's technical support. My power-supply has 36A at +12v.