I'm looking to build a high-performance rendering machine. Is it possible to have 3 graphics cards in SLI? (I'm sticking to nvidia). If so, can someone recommend a good motherboard/gpu combination for that system?

What do you mean by "high-perf rendering"? What sort of rendering do you want to do?

I'm doing a lot of shader-intensive rendering to FBOs, which I then copy to a memory buffer using PBOs, compress that and send it over the network.

Just go with an NVidia 9x series card (actually, I'd suggest to hold off until NVidia's next gen cards get released within a month), and a tri-sli MB (so yes, you can have 3 graphics cards in SLI).

Not exactly what I'd call high end, but a good gaming system computer. The NVidia Quadro's are more high end, albeit they are horrible for video games. For one of those cards, you're probably talking around $1000-$2000 per video card. Plus, throw in the Xeon processor, Raid HD's, etc, we're talking $20000+ for a computer.

You can even go higher end than that, but those are out of the range of what the majority of people on this site would need.

I think you'll find this blog post of Dan Green's setup helpful :P

Don't get the Quadro series. They're mainly meant for speeding up 3ds max and other modeling app's viewport rendering and dealing well with high poly scenes. However, they are terrible for anything else. So unless you're a modeler, they will do you no good.

Quote: they are terrible for anything else

That has not been my experience. My experience has been that a given Quadro is just as good for games as the equivalent GeForce. The problem is, there are a lot of Quadros for sale that are 128 bit, or even 64 bit -- their equivalents would be the GeForce 8400 or below! If you get the high-end, 256-bit Quadro boards, they are just as good for gaming as the 256-bit GeForce boards.

Quadros also give you increased driver support for DCC applications (overlays for Maya, etc), video Genlock, and higher quality components/assembly. They are four times as expensive, though.

If you want the ultimate GPGPU system, you should look into the NVIDIA PLEX systems. They start at $20k, though -- and that's just for a single plex rack. You can put three of those in a single machine, I think.

I concede, it seems i was quite wrong in that respect ( as was a few others here).
FX 5600 video game benchmark. It seems the fx 5600 is quite comparable and is better than the 8800 gt, although the benchmarks were done on a mac.
Now, my question is, did they use the standard quadro drivers or did they use the geforce drivers? I've always heard it is the drivers which offer the main tweaks in 3d apps and lower performance in games.

...my eeePC does really high end rendering...:P

Quote: Original post by Gaiiden
I think you'll find this blog post of Dan Green's setup helpful :P

Wow that's just wicked!