_hollish

Just in case anyone finds this thread while dealing with similar issues, a new motherboard fixed the issue for me. It took a while, but unraid was finally able to finish the parity calculations. I suspect the SATA controller on the motherboard was the issue to some extent, so it's possible that a different controller (like an LSI card) would resolve the issue with less cost. I wound up having to order one anyways, since my new motherboard doesn't allow use of all 6 SATA ports if you're running 2 NVMe drives as well. I probably won't try the old motherboard again though, since I've already put enough time and money into troubleshooting the issue.