Motherboard that supports peer-memory access across 3 or more PCIe 2/3 x16 devices

I am writing some code that abuses the peer-memory access mechanism introduced in Fermi. I have only been able to test it with 2 GPUs so far. I have 4 C2070 Tesla devices but I have not found any motherboard with a single IOHUB (required to have peer-memory access between all of them) that supports 3/4 PCIe devices in x16 mode. Does anyone know a motherboard model that supports this configuration?


I was never entirely clear on how this worked, but I thought it was only the dual-socket motherboards that had multiple “IOHUBs”. What have you tried so far?

The only 4 x16 (and 3.0) motherboard I am aware of is the ASRock Extreme 11. It has a single x79 chipset plus two PCIe switches.

I got the ASRock Extreme 11 and it is working as advertised. Thanks a lot.