So odd thing happened; a few weeks ago computer started randomly crashing on idle. Ran VT3 overnight no errors on the old timings after symptoms appeared. VT3 would only fail with Furmark also running in the background–a trick I've picked up in the past to accelerate debugging SoC and PHY instability.
Flash BIOS with new revision, port over old sub-timings, PBO offsets, LLC "Normal" settings, and initial training values but increased tCL to 32 and tRP to 36, but decreased VDD to 1.4. My suspicions were heat related, as heat soak messes with PHY.
The final new looser timings at a lower voltage were still failing full tilt VT3 + Furmark after a few hours, but passing overnight on just plain VT3. Finally I solved it by leaving Nitro settings on their default of 2/3/1. Now passing full tilt VT3 + Furmark overnight. Curious if my original settings would have still worked with the lazier PHY timings.
Has this happened to anyone before?