Hey all, we have created great cards for Mac Pros and I finally got ahold of a 3,1 X-Serve. I didn't really understand the noise about the noise until I fired it up. Man that thing is loud ! Anyhow, I have been curious about which EFI these machines used and how the MXM slot works. Very interesting bunch of things I discovered. It is possible to use an EFI card and have boot screens CUDA, etc on 3,1. Can't speak for 2,1 and earlier. But I was very interested in the MXM slot. It turns out Apple did a crappy thing and only ran 2 PCIE lanes to it. I would be thrilled to find that the Dual CPU models got 4 as I only got a single CPU model, but I doubt they bothered. So even when I put a GTX980M in the MXM slot I got minimal CUDA/OpenCl out of it. I think the Nvidia cards will require some display remapping to output through the MDP connector, but the AMD 6970M did it just fine unflashed. I have to apologize, definitely came to the party after everyone went home. I imagine these things are getting shredded for the most part. The unimaginable noise makes them unthinkable for home use, except in a distant room. It is possible to use GPUs with CUDA and OpenCl support but not sure there is much need for that. Would love to hear differently. I am hoping to write a GT630 EFI/BIOS to enable basic display and CUDA functions, might help some folks.