Riser cable

[nuzik]

Should i need to set my bios to the correct PCIE gen of the riser cable, 

i have a gen 4 cable and my graphics card is gen 4 but my mobo supports gen 5. 

[ItTakes2ToMango]

No, it will work fine without any additional settings needing to be changed

[nuzik]

I thought the same it's worked fine but there have been some issues with spikes in power and then it causes problems. I just had an hours gaming with no issues. Since I changed my bios to pcie 4 for the lane my riser is on.

Needs more testing 

[mariushm]

There are quite strict rules about how long traces can be between cpu socket (which has the pci-e controller) and the gpu chip, the length of the traces on pci-e 5.0 must be very short.

The riser cable may add too much length or the extra resistance of the wires may degrade the signal enough to just not work at pci-e 5.0 levels.

[manikyath]

if your motherboard is 5.0, the gpu is 4.0, and the riser is 4.0, there shouldnt be any issue, because the gpu will negotiate 4.0 anyways.

 

however, if your motherboard and the gpu both are 5.0, and the riser is 4.0, the gpu will try to negotiate 5.0, and you might have rather severe signal problems over the 4.0 riser. so inthat case, you'd have to set that to 4.0 manually.

[nuzik]

The 7900 xtx should be pcie 4 and thr motherboard in the only one thats 5.