[Dash8Q4]

I just installed a new gpu waterblock and used a phanteks PCIe 3.0 x16 riser cable. I then realized my card is running at x8 instead of x16 and I'm scratching my head as to why. Initially I had issues booting with video signal as my motherboard is an Asus Tuf Gaming x570 Plus Wifi and the gpu is a 3080, both being gen 4 with a gen 3 cable between them. I set the pcie to gen 3 in the bios and problem solved. Now I see the gpu running at x8 instead and need help figuring it out without having to drain my loop and plug the card directly to the motherboard. My system is a Ryzen 7 3700x, 16gb ram, I have two m.2 ssd's one Gen3 and one Gen2, a sata ssd and two hdds.Today I received a gen 4 riser cable and plugged it in, changed bios to auto and the card is running at gen4 but still x8.
I updated the bios on the board, no change. The card is connected to the top slot(closest to CPU) I removed my gen3 m.2 and nothing changed, it doesn't affect the bandwidth it seems.
Tomorrow I'm going to troubleshoot some more by removing the sata drives and also reach out to Asus about this issue. I'm thinking of putting the card into the motherboard slot directly just to knock that off.
About three months ago I got a SiliconPower US70 gen 4 m.2(got it for half price, it was a review sample) which gave me BSODs every time I tried to start gaming. I RMA'd it and the same thing happened no matter what Gen I set the m.2_1/2 in the bios. In the end, I gave it to my brother when I built him his rig which only supported gen3 drives and no BSODs. I let this go as I don't think I'll be needing a gen4 drive anytime soon or ever for that matter. But now I might bring that up with ASUS as well in case the board is faulty.

Any help will be much appreciated.

 

[Blameless]

Try the card installed directly in the slot, to rule out an issue with the risers, and in another system to rule out an issue with the board/CPU. Reseating the CPU may also help. Also try running the CPU/memory at stock if you have not (PCI-E controller is part of the SoC die and an unstable SoC, FCLK, or poor contact with any related pins, can potentially cause issues).

 

[Avacado]

What MOBO do you have? Still the X570 Tuf? And what card did you use previously?

 

[ajlueke]

You need to read the documentation on your motherboard carefully. Ryzen systems have a limited number of PCIe lanes, and often the motherboard will drop the GPU speed if both m.2 ports are populated. The same thing happens on my X470 Crosshair VII. If the first M.2 is populated, the GPU will run at X16, if the second is populated, it will run at X8.

 

[Pinnacle Fit]

You need to read the documentation on your motherboard carefully. Ryzen systems have a limited number of PCIe lanes, and often the motherboard will drop the GPU speed if both m.2 ports are populated. The same thing happens on my X470 Crosshair VII. If the first M.2 is populated, the GPU will run at X16, if the second is populated, it will run at X8.

I have two M.2 installed. They’re both running at x4. I’m still getting 16x on my gpu


Sent from my iPhone using Tapatalk