Z77 Extreme 4 + 480 no POST with PCIE 2.0 top slot

papryczka wrote: Hi, I recently upgraded my 2600K running on a Z77 Extreme 4 Mainboard from a 560Ti to a Gigabyte G1 RX 480. The UEFI is the latest 2.90, I also tried the 2.90M Beta. The problem is that the system won't POST and is stuck with error code A9 or d7, mainly A9. Only when I force the PCIE2 (top slot, electrically 16x) to Gen1 the System starts up normally. Also moving the card to the PCIE3 (lower slot, electrically 8x only) makes it work (with PCIe Gen2). I tried already enabling/disabling CSM with the various options in the Beta UEFI and various PCIe Generation settings, but nothing makes it POST, except the two methods mentioned above. The really weird thing is that the first time I plugged in the new card it worked flawlessly with 16x and Gen2 in the top slot. Only after loading UEFI defaults it stopped... The card itself works in 2 other systems. Also the Z77 Extreme 4 still works properly with the 560 Ti in the top slot. Does anybody know a possible solution for this (especially since it already worked once)? Is there any other Beta UEFI available? Any help is appreciated!

New model video cards like your 480 tend to have problems on older boards. The reason(s) are not perfectly understood. You are lucky that your 480 works at all, some new video cards don't function at all in older boards.

In some cases a part of memory reserved for system use is not large enough to deal with the needs of the new video card. That is, the TOLUD (Top Of Lower Usable DRAM) value is not "high" enough. Some board's UEFI/BIOS allow TOLUD to be adjusted, but that is not common on older boards.

The d7 POST code is the mouse or keyboard was not recognized. A9 is a SATA or other storage related POST error. Are you using an NVMe SSD, or just SATA drives?

Why did you try changing the CSM option to fix the issue?

You seem to know you are limited to PCIe 2.0 support with an i7-2600K. Do you have Gen3 as an option for the PCIE2 slot? If you do, you could try it but no guarantees.

The question is, if a setting in the UEFI/BIOS that was reset when you loaded UEFI defaults, allowed the 480 to work. That loading the defaults caused the card to stop working at Gen 2 x16 hints this might be a UEFI/BIOS NVRAM issue.

To fully clear the UEFI/BIOS and its NVRAM, shutdown the PC and remove it from AC power. Move the UEFI/BIOS clear jumper to the clear position, and remove the battery from the board. Let it sit without the battery for 10 minutes or more, then install the battery and move the jumper back to its normal position.

Did you uninstall the Nvidia video driver you were using before installing the 480? You had an Nvidia driver installed, and now have an AMD/ATI card. You really should run the DDU program to uninstall your old Nvidia driver, just search on "DDU" to find a download site.

You may have done some of the following, but you did not mention it if you did.

The best process would be, remove the 480 and connect to the Intel iGPU. Clear the UEFI/BIOS with the jumper while removing the 480. You'll be prompted to use the UEFI/BIOS after doing the clear, so you could go in and set the Primary Graphics Adapter setting to Onboard. Boot into Windows and run DDU to remove both the Nvidia and AMD drivers, then do the full UEFI/BIOS clear. Restart the PC after running DDU, to be sure it boots.

Finally, install the 480 again, and then install its driver.

There are no other Beta UEFIs available. Both of the 2.90 UEFI versions add things unrelated to video cards.