Strix X870E-E and RTX 5080 PCIe Lanes and Speed problem

[Javi7269]

Hello, I have an Asus Strix X870E-E Gaming Wifi motherboard and recently purchased a Gainward RTX 5080 Phantom. Everything seems working fine except for 1 problem:

On cold boot, my RTX is running only at PCIe X8 and 4.0 Gen. and restarting the computer it gets back to normal.

It seems to hapen every cold boot or first start and gets back to normal after restarting.

Looked into Google and I saw there are many users having this issues with RTX 5090 and 5080 but a lot other users don´t have the problem at all.

Changing PCI speed, forcing PCIe Gen5 in BIOS doesn´t work for me. Changing in BIOS to PCIe Gen4 didn´t work.

Tried to disable fast boot on windows and BIOS but no luck.

It seems to me that it´s a BIOS problem, I don´t know, that´s why I´m asking here to other members if you have this same problem or if it´s OK for you with RTX 5000 series GPU´s.

Or maybe is a Nvidia GPU Bios problem and should wait for a fix from Nvidia ??

Is there any other thing I could try ??

My BIOS is up to date on 1203.

My CPU is Ryzen 9 9950X3D

Ram Lexar Ares 2 6000 MT/s. CL26, 32GB (2x16GB)

Nvidia GPU is Gainward RTX 5080 Phantom connected with 12V 2x6 pin cable on NZXT C1200W ATX 3.1 and PCI 5.1 compatible.

Thanks in advance

[Fastkill55]

Hello, i have same problem but with different RTX 5080 card MSI trio. Same think after cold start I get 8x lanes, but after play games and restarting pc I get full 16x. 

Them I turn off pc waid 5-10 min and strat up, same think 8x lanes. After start game, turn off game. And restart pc I got 16x again. It's so weird. I thin too somethin is buged. BIOS, windous etc in som component combinations

Maybe later BIOS update or drivers fix it.

I tired everything 

GPU swap, CMOS, setting, swap nVME SSDs... Nothing

I tried old GPU in new system, them I get 16x on cold start. Same for new GPU in old system 16 lanes. But new GPU in New System z890 carbon WiFi. I get only 8x on cold start. 

[Zheega]

I have a similar problem with my 4080S and the Radeon 6800XT before that on my B650E-E, only that the problem manifests in GPU being stuck in 16x v1.1 mode, usually on cold boot, but sometimes after exiting standby. A restart will either completely solve the problem, or the PCIe will be stuck in 16x v2.0 or v3.0 mode. But when it is in 16x v4.0 mode, everything runs perfectly no matter how many benchmarks and stress tests I run.

Something is broken with initialization on these motherboards.

[oliviamais68]

Had a similar issue with a client at our Roblox Game Dev Agency UK turned out to be a quirk in early BIOS revisions with PCIe negotiation on cold boot.