Asus x670e Hero Crosshair GPU Shows PCIe 5 x 8 lanes not 16 lanes

[marcusob72]

Plugged a 5090 into my x670E AMD Compatible CrossHair Hero motherboard, and in GPU-Z (2.64.0) it is showing as a Gen 5 Slot supporting 16 lanes, but is configured as PCie Gen 5 with 8 lanes 

PCIe x16 5.0 @  x8 5.0

What difference will this make to the speed of the 5090 ? Will it be half bandwidth - does the 5090 use all 16 lanes ? I have a 10Gbe LAN card plugged into the PCIe slot.

[KedarWolf · Accepted solution]

You lose maybe 1-2% of the performance being 8x I mean.

[TrickMasterPC]

I made a video that covers the lane sharing, splitting, bios pcie and m.2 config https://youtu.be/AKy00PpIISA?si=1jqp0JWhwRGTRFQx

[purecain]

8 lanes in PCIE 1, 16Lanes in PCIE 2, PCIE 3 doubled the bandwidth even though only 16 lanes were used, PCIE4 is again double the bandwidth, x8 is 16 PCIE lanes, PCIE 5 offers advances in power and efficiency. This is off the top of my head. Im gonna watch the video you posted. 

It says video unavailable. Please reup!

[TrickMasterPC]

Here's the video https://youtu.be/AKy00PpIISA?si=1jqp0JWhwRGTRFQx