If you're getting a single video card, or one for calculation and one just to do video, make sure motherboard has 16 PCI-e rel3 lanes into the primary card, peo

If you're getting a single video card, or one for calculation and one just to do video, make sure motherboard has 16 PCI-e rel3 lanes into the primary card, people are using z170 and z97. For 4 video cards, you want x99 mobo, newegg does a good job of standardizing different mfrs' specs e.g. http://www.newegg.com/Product/Product.aspx?Item=N82E16813132263 http://www.newegg.com/Product/Product.aspx?Item=N82E16813132... Other concerns: you want a full size cage, with the SSD drives all the way at the top, out of the way of the video cards (the largest Nvidia OEM 3 fan cards are almost 13" long, so there's going to be some Tetris if you want a lot of drives and video cards in there). Cooling critical, stuff the box with RAM and Xeon's or i7s. This is a good tip: older Xeon servers, dual socket, can support good PCI bandwidth with 2 CPUs: https://news.ycombinator.com/item?id=12606481 https://news.ycombinator.com/item?id=12606481