Question Regarding PCI 4.0 and Risers

[LemDog]

Hey everyone!

 

I am working on a new SFF build and have decided on the SM580 from Sliger. My question there was, they currently only offer a PCI 3.0 Riser. The board I am looking at from ASUS has a PCI 4.0 Port. Is that going to cause me any issues? I have no experience with PCI Risers. Any advice here would be helpful!

 

Regards,

LemDog

[BTGbullseye]

A PCIe 3.0 riser will only handle PCIe 3.0. It will cause any connection between the motherboard and GPU to max out at PCIe 3.0. If you want PCIe 4.0 on a riser, yuo will have to get a specially constructed riser cable, and maintain a cable temp (not GPU temp) below the limits they specify. (usually around 50°c) Most manufacturers recommend against their use in SFF systems due to the difficulty in keeping the cable temp low enough to maintain PCIe 4.0 connections, and exceeding that temperature will drop it down to PCIe 3.0 speeds.

 

Of course, if you're not using a CPU (Ryzen 3000 series) and GPU (RX 5000 series/RTX 3000 series) that have PCIe 4.0 capabilities, then it's pointless to worry about.

[LemDog]

Thanks dood! Everything I needed to know! I was going to be getting the new Ryzen 5900 and a 3080 so this might cause me some problems. I might need to rethink my build again! Thanks again!

[Random_Person1234]

1 hour ago, LemDog said:

Thanks dood! Everything I needed to know! I was going to be getting the new Ryzen 5900 and a 3080 so this might cause me some problems. I might need to rethink my build again! Thanks again!

PCIe 3 and PCIe 4 don't make a noticeable performance difference for the 3080.

[LemDog]

Hey @Random_person1234 While I have heard the same wouldn't that not be true for bifurcation of a single 16x PCIe 4.0 slot? Due to it being MITX I wanted to make sure to maximize what I was getting out of that single port I have.

 

Regards,

LemDog