The best article I could find for this technology comes from PC Perspective. Note, many review sites do have some details wrong.
This is nVidia’s Detail:
Tesla C870 is the card.
Tesla D870 is the previous QuadroPlex design (2 Tesla C870 cards).
Tesla S870 is the 1U rackmount (4-8 Tesla C870 cards).
According to nVidia’s website, there is no mention of PCIe Gen 2, although the review sites claim this technology will be used for the D870 and S870 adapter cards. This might be another option, in which the user can choose from 8x and 16x PCIe Gen 1 and 8x and 16x PCIe Gen 2.
A worthy thing to note is nVidia’s suggestion to keep a 1 GPU to 1 CPU core ratio. Considering Supermicro has released a 1U rackmount featuring 2 motherboards, each with 2 sockets for Intel’s Quad Core Xeon 5300’s, a 16 GPU and 16 CPU setup can be achieved in just 3U (using 1 of Supermicro’s SuperServer 6015T-TV with 2 Tesla S870 with 8 GPU’s each). Thats 8 TeraFLOPS of GPU power alone in 3U.
A correction needs to be made. It appears that an adapter is needed for every 4 GPUs. Considering the design I gave above only supports 1 PCIe 8x slot per motherboard, the design would be impossible (if not impossible, the link would be a huge bottleneck). Hopefully Supermicro or Tyan will introduce a similar design to the SuperServer 6015T-TV that features 2 PCIe 8x/16x Gen 1/Gen 2 connectors per mini-motherboard.
Congratulations to nVidia on a well developed dense computing product.