Hi, I contacted support three days ago, but classic Asus support won't respond to anything, so I thought I would try the forum. My Asus B550-E motherboard's second PCIe x16 slot is stuck at x4 Gen 4 speeds no matter what I do. I have a Ryzen 7 5800X and an RX 7600 and 4080 Super, one NVMe SSD, and one 2.5-inch SSD. I have tried the second slot with either GPU, and it is the same result; in the top slot, they work at intended speeds. I have updated the BIOS, reseated the CPU, cleaned the slot, made sure it is not damaged, and nothing is working. I can't understand why the second slot is not going to x8 Gen 4 speeds, even though it is able to and it is stated everywhere. I checked the CPU to make sure there weren't any bent pins; there weren't. I also checked the socket to make sure it was clean, and it was.
In the BIOS, there is an option for PCIe bifurcation, but there is no option for x8 x8; only RAID, Auto Mode, and x8 x4 x4 are available. I have it on Auto mode; I even tried x8 x4 x4 to see if the name was wrong, to no avail. I even checked the pins in the second PCIe socket when inserting the card to make sure they all lifted up, which they do, meaning they make contact. I looked at the results in GPU-Z. Even under load, any card in the second slot only shows x4 running at Gen 4 speeds. I really do not understand what the problem is.
Can someone help me?
