Mother board advice for newx570, 5950 build (PCIE lanes)

[WalkerYYJ]

Budget (including currency):  High

Country: Canada

Games, programs or workloads that it will be used for: Custom VR environments, high end simulation (high single core demand), VMs

Other details :

Hey all, having some issues deciding on an x570 for a new build for a 5950.

Id like to be mindful of “adequate” memory overclocking (don’t need to set any records here but id rather not leave a bunch of potential performance sitting on the table unused.)

It will be running some heavy lifting single core tasks (custom VR stuff) along with some all core rendering and VMs etc.  Not super constrained on $$$ but id like to keep this on AM4 vs going to SP3 (single core performance is top priority).

GPU will probably be 3080/3080. I want to run a pcie capture card (probably elegato 4K60 (PCIE x4) and (ideally) a 4 port full speed USB expansion card PEXUSB3S44V (PCIE x4). I can probably get by with a 1G or 2.5g NIC (10G would be nice but I’m not convinced that’s going to be in the cards from what iv been able to hunt down so far.) Don’t care about wifi.

1TB of fast storage should be enough.

Min 64gb Ram (TBD on what)

I was looking at the dark hero but id have to go to run the 3080 on x8 and from what I “think” I understand of this, even with PCIE x4 that would be limiting memory performance in high workloads on the 3080 (how much is unclear to me.)

 

So should I not worry about the x8 on the 3080? Is there another MB out there with more open lanes? Do I need to loose the Elgato card and run capture off of USBC?

 

Thanks!

[Lurick]

The top PCIe slot should pull direct from the CPU at x16 and then the other slots should be wired to the chipset and pull from there with PCIe 4.0 x4 lanes between the CPU and chipset but double check on the second slot and make sure

[WalkerYYJ]

3 hours ago, Lurick said:

The top PCIe slot should pull direct from the CPU at x16 and then the other slots should be wired to the chipset and pull from there with PCIe 4.0 x4 lanes between the CPU and chipset but double check on the second slot and make sure

The concern I have is not being able to supply enough PCIE lanes, https://rog.asus.com/us/motherboards/rog-crosshair/rog-crosshair-viii-dark-hero-model/spec/

 

Having a hard time finding an MB that would allow 1x16 and 2 others at x4

[Lurick]

11 hours ago, WalkerYYJ said:

The concern I have is not being able to supply enough PCIE lanes, https://rog.asus.com/us/motherboards/rog-crosshair/rog-crosshair-viii-dark-hero-model/spec/

 

Having a hard time finding an MB that would allow 1x16 and 2 others at x4

The PCH/chipset allows for 20 extra lanes but the speed of those 20 lanes is limited by the interconnect of 4x PCIe 4.0 lanes to the CPU.

 

Edit:

It looks like the top two PCIE x16 slots are wired to the CPU.