I posted this on Reddit where it's gotten around 200 upvotes and tons of comments with people having the same problem. I'm posting it here to make MSI aware of the issue as well, even though it affects all motherboard vendors. I already reported this to AMD and Nvidia.
With PCIe set to either Auto or Gen 4, and when using a PCIe 4 GPU such as a 3080, many people are having problems with USB devices - mostly on USB 2.0 ports but sometimes on 3.0 ports as well. I'm seeing tons of reports of this problem (some of which go back a whole year!). It doesn't seem limited to one specific vendor either.
For me personally, I have a 3080 FE, 5900X, and MSI Tomahawk X570. I am experiencing audio dropouts when streaming a game on Discord. The audio drops for both people viewing and also for me, the one playing the game. That problem almost entirely goes away if I move the USB dongle for my headset from a USB 2.0 port to a USB 3.0 port. I also get occasional tracking loss on my Valve Index in VR when trying to view desktop windows from within VR. All of my VR devices are connected to USB 3.0 ports on an add-in card. This is a brand new windows installation with all updated drivers.
Setting PCIe to Gen 3 in the BIOS fixes the problem entirely. Disabling Global C states has no effect, only limiting PCIe to Gen 3 fixes the issue. Raising/lowering voltages for things like SOC doesn't make a difference either. I see a lot of discussion about the Global C State issue including vendor comments from Gigabyte and MSI, but so far no vendor has commented on the PCIe Gen 4 issue. Hopefully this issue starts getting some more attention as more people get PCIe Gen 4 GPUs. Limiting myself to Gen 3 isn't the end of the world, but people shouldn't have to lose that 2% of performance just to have a properly functioning system.
Here are some of the many reports I have seen of the issue. There are a lot more, this is just a small sample:
With PCIe set to either Auto or Gen 4, and when using a PCIe 4 GPU such as a 3080, many people are having problems with USB devices - mostly on USB 2.0 ports but sometimes on 3.0 ports as well. I'm seeing tons of reports of this problem (some of which go back a whole year!). It doesn't seem limited to one specific vendor either.
For me personally, I have a 3080 FE, 5900X, and MSI Tomahawk X570. I am experiencing audio dropouts when streaming a game on Discord. The audio drops for both people viewing and also for me, the one playing the game. That problem almost entirely goes away if I move the USB dongle for my headset from a USB 2.0 port to a USB 3.0 port. I also get occasional tracking loss on my Valve Index in VR when trying to view desktop windows from within VR. All of my VR devices are connected to USB 3.0 ports on an add-in card. This is a brand new windows installation with all updated drivers.
Setting PCIe to Gen 3 in the BIOS fixes the problem entirely. Disabling Global C states has no effect, only limiting PCIe to Gen 3 fixes the issue. Raising/lowering voltages for things like SOC doesn't make a difference either. I see a lot of discussion about the Global C State issue including vendor comments from Gigabyte and MSI, but so far no vendor has commented on the PCIe Gen 4 issue. Hopefully this issue starts getting some more attention as more people get PCIe Gen 4 GPUs. Limiting myself to Gen 3 isn't the end of the world, but people shouldn't have to lose that 2% of performance just to have a properly functioning system.
Here are some of the many reports I have seen of the issue. There are a lot more, this is just a small sample:
Code:
https://community.amd.com/t5/processors/audio-crackling-and-usb-issues-with-pcie-gen-4-0/m-p/421978#M33917
https://www.reddit.com/r/AMDHelp/comments/e598ho/pcie_gen_4_and_rx_5700_xt_issues_affecting_usb_20/
https://www.reddit.com/r/MSI_Gaming/comments/k026eo/b550_edge_gaming_wifi_insane_usb_stutter/ge8q5bo/
