The motherboard is a Supermicro X9DRX+-F. They have an X10 version also, it’s basically the same but uses more expensive Xeon E5 V3/V4 and DDR4 Ram. I stick with X9 boards and super cheap Reg ECC DDR3
It has a total of eleven [11] PCIe 8x slots. 10 of them are PCIe 3.0, and the top 11th slot is PCIe 2.0 (4x electrically). You can use all slots at full lanes at the same time. I only limited myself to 8 cards because I was a little worried about power draw from the PCIe slots. I’m using an EVGA power injector on the PCIe 2.0 11th slot, and normal USB risers which don’t use power from the slot for slots 9 and 10.
Specs here:
https://www.supermicro.com/products/motherboard/Xeon/C600/X9DRX_-F.cfm
I do not have it in a case. I’m using it on a mining rack (shown in pics). Cases for this board do exist from Supermicro, but they are expensive ($1000+), and rarely show up on the used market, still expensive when they do. But if you want to put more than 5 GPUs you’ll need to do some custom stuff like risers or single slot watercooled cards. There’s no single elegant solution.
I keep hoping to find PCIe 3.0 (ie, shielded) riser cables that have external power connections. But it seems no one wants that except me lol
