I assembled a system using P4304CR2LFKN chassis, two Xeon E5-2620 CPUs, 32GB (4x8GB) RAM and four GTX690 graphics cards. It's running Windows 7 Pro SP1 x64, with the latest drivers from Intel and NVidia. However, I have several problems:
1) The only BIOS version which works at all is 01.02.2002, dated 5/1/2012. Anything newer and BIOS gives an error "0146 PCI out of resources error" on startup, and Windows does not see any GPUs, regardless of the value I set for IO space allocation above 4GB.
2) BIOS is not accessible using an add-on graphics card - both analog and digital connections output random noise during POST. I have to remove all add-on cards and use the onboard video in order to enter BIOS setup and configure settings.
3) When I install more than two (i.e. three or four) graphics cards (total six to eight GPUs), applications that use 3D acceleration or CUDA stop working. Whereas with two graphics cards (four GPUs) applications such as Octane Render run fine, adding another card either produces blank screens, or crashes on startup. Additionally, when three or four cards installed, shutdown process results in a reboot rather than power down, and after the reboot Windows displays a message that there was a blue screen crash.
How do I get this system to work with eight GPUs (4xGTX690) for running CUDA workloads? I don't need SLI, just CUDA.