Hey everyone, I am trying to be sure I have my x16 PCIE lanes from my CPU split x8 to the top slot and x8 to the bottom slot. The setting in the bios has x4+x4. I am assuming that is the same thing. Pardon the photo of a monitor, its my server. Edit-Spelling
Nope, that’s not what’s going on here.
Both slots (labeled as PCI_E1 and PCI_E2) are bifurcated (=split into multiple sets of independently operating lane groups) in two sets of four lanes each.
In the displayed configuration you can operate 4 devices connected with 4 lanes each to the CPU.
The manual isn’t really helping to clarify the situation. The key sentence is on p.16 : Supports x16/x0/x4 or x8/x8/x4 (For Ryzen™ 7000 Series processors)
What this weird sentence means to express is that if the first slot is populated with an adapter card, and the second slot is empty, the first slot is electrically equipped with 16 PCIe lanes which are connected to the CPU (Supports x16/x0/...
).
If there are adapter cards both in slot 1 and 2, a switch will automatically redirect 8 CPU lanes to the second slot, so both slots will operate with 8 PCIe lanes each (or x8/x8/...
).
Your BIOS/UEFI settings will split the 8 lanes available to each of the two slots even further and allow operating special bifuraction adapter cards that e.g. have two m.2 slots for nvme drives.
Unless this is what you want to do, I’d change the “PCI_E(1/2) Lanes Configuration” settings to their default value, probably called “Auto”, but the manual does not list that.
Awesome reply. Thanks! Ill go back and change that in bios when I’m done watching this movie. Much appreciated!!!