My previous computer died, so I started a new build in anticipation of Zen 3 using a Ryzen 5 2600 I picked up inexpensively. I currently have the following:
Ryzen 5 2600
Gigabyte Aorus x570 Master
Corsair Vengence RGB Pro (CMW32X4M4C3200C16) 4x8GB
When I boot into windows, it shows that I have 32GB ram installed but only 16GB usable. I played around with the ram and discovered the following:
1. Inserting each ram stick individually into slots A1 or A2 caused no problems and works as expected (single channel but all capacity as expected)
2. If I put a stick solely into slot B1 or B2, the system will not post. The LED cycles through ~4 values infinitely. I don't have them written down.
3. As long as there is a dimm in A1 or A2, the motherboard will post. Any memory placed in B1 or B2 is not used.
4. I reinstalled everything onto a different motherboard (ASUS TUF x570 plus). The memory slots are ordered opposite the Gigabyte board. The A slots neighbor the CPU on Gigabyte, and the B slots neighbor the CPU on ASUS. Now if any dimm is placed in the B slot of the ASUS board, it will not post.
I believe this indicates that the problem is not with the motherboard or ram, and must be the CPU. Is that a reasonable assumption? Is there anything I might be able to do to rectify the problem, or would it require an RMA with AMD?