X299 PCI Slots

ksnyder wrote: I have an Asrock Taichi motherboard with a 7820x processor. Can I place my single graphics card in any slot to get 16x speeds or does it have to be in Slot 1? I would like to move the graphics card down to get it away from my CPU cooler, but I don't want to sacrifice speed in order to do so. Thank you. Kevin

There are three factors involved here, but only one of them is your choice.

First, you have an i7-7820x, that provides 28 PCIe 3.0 lanes for the PCIe 3.0 x16 slots.

Next, the specs of the PCIe 3.0 x16 slots of the X299 Taichi:

1. If you install CPU with 44 lanes, PCIE1/PCIE2/PCIE3/PCIE5 will run at x16/x8/x16/x0 or x8/x8/x16/x8.

2. If you install CPU with 28 lanes, PCIE1/PCIE2/PCIE3/PCIE5 will run at x16/x0/x8/x0 or x8/x0/x8/x8.

3. If you install CPU with 16 lanes, PCIE1/PCIE2/PCIE3/PCIE5 will run at x16/x0/x0/x0 or x8/x0/x4/x0.

Only the PCIE1 and PCIE3 slots can be allocated up to 16 of the PCIe 3.0 lanes from the CPU. But the number of PCIe lanes available from the CPU determines the PCIe 3.0 lane allocation to each of the PCIe x16 physical slots. With your i7-7820X CPU, that is the allocation in number 2, above.

Finally, it is generally accepted that the difference in performance of any current video card between a PCIe 3.0 x16 and a PCIe 3.0 x8 interface is very small, or none at all. So you can use the PCIE3 or PCIE4 slots, which are PCIe 3.0 x8 with your CPU just fine IMO, but that is up to you.