Will seven GTX 480 cards work under XP64 ?

I’m in progress of building the dedicated workstation for CUDA-based calculations and going to build it on EVGA Classified SR-2 motherboard (7 PCI-E slots, two 1366 CPU slots). It seems that this motherboard will successfully work with seven GPUs (seven GTX 480 cards, one card per PCI-E slot) but it is not clear whether XP64 (or Vista or 7, whatever windows platform) will detect all seven cards.

Guys that built Fastra and Fastra II worked with 8 GPUs under XP64 (they used four cards with two GPUs each for Fastra), does that mean that seven GTX 480 should also work under XP64 or Win7_64?

Thanks in advance.

Most powerful GPUs are dual slot cards… so you can’t put 7 cards into that motherboard physically.
The Fastra guys went through severe pain with riser cables and such for their funky system.
And for them, the BIOS had problems with 8 cards, which they hacked around with custom OS kernels.

BUT asking about your original question, will XP see 7 cards? Yes, probably it will. W7 will probably too with the latest drivers (though this was a big issue for a full year).
I don’t know if anyone has done that ever though. (4 GTX295s, yes, but not 7 physical cards in Windows).

In practice… such machines are high risk low reward hack hardware devices. The practical limit, just from hardware, is likely 4 cards and even that takes effort.

You could argue that SOME apps might benefit from a 7 GT240 GPU system… that’s the sweet spot for single-slot cards and they’re quite low wattage especially for their FLOPs. But I doubt any MB could supply the needed 7*~60=420 watts via the PCIe slots since these boards don’t have external power connectors. It’d be interesting to try!

In fact, it is possible to put 7 water-cooled cards in one motherboard without risers (check out this sample, it shows four dual-slot cards but that’s only because of absence of single-slot PCI brackets on the moment of assembly).

Also, EVGA product manager says that SR-2 will work with seven GTX 480 cards. This system is to be built for a particular task with particular software, it is better to have 7 cards and two CPUs in one system instead of building two workstations with four cards and one CPU each (with subsequent modification of software to make it functional over the network).