4 GPUs

Is there any system available on the market right now that can have four 8800 gt cards. Could CUDA run on all of them?


Ok, I forgot to mention, except Tesla. Too expensive.

You’d have to find a motherboard with four PCI-express 16x slots. It wouldn’t surprise me…

All the motherboards I’ve seen with four physical 16x PCI-E connectors will downgrade some of the slots to 8x communication if they are all filled. Also, if you expect your CUDA jobs are going to be GPU memory bound, you might find that 3 GTX cards (with the 384 bit bus) would perform better than 4 GT cards.

I believe the question was ‘available on the market now’, so Tesla is not a valid answer.

The 1 and 2 GPU versions should be available but are not despite “The NVIDIA® Tesla™ C870 GPU Computing processor and D870 Deskside Supercomputer will be available in October 2007.” And the 4 GPU version will come out in december (but given the above I have not a lot of hope for that)

As you maybe understand, I am waiting for the Tesla cards to come out, as I see great potential for them in our products.

The MSI K9A2 Mainboard with the AMD 790FX Chip supports 4 GPUs max.
But there are some constraints on the PCI-Express 2.0 lanes.
If you use 2 GPUs each card will have 16x lanes available, but if you put in the
max. of 4 GPUs, each card will only get 8x lanes.

Indeed, it depends, the loss of half of the transfer speed to each individual card might be worth it having 2 times the processing power in a lot of cases. Note that the total bandwidth to/from the cards remains the same.

The MSI P6N Diamond has 4 x16 mechanical slots - but 3 slots drop to x8 when fully populated.

We have an ASUS P5N32-E SLI which, in theory, can handle 4 cards. Currently we have 2 cards installed and we’ll be adding 1 more in the future. Because the GLX is 2 slots wide, cooling will be a problem: there is hardly any space between the cards.
If we need more than 3 cards, we’ll just have to add a new server to our network.

I’ve used 4 GPUs (two QuadroPlexes) attached to a dual-dual core Opteron machine with good results. This only requires two PCIe x16 slots. We haven’t tried any of the new motherboards that have four PCIe slots yet, I’d ask the NVIDIA folks which motherboards are well-suited to this as they may have suggestions in this regard.