I recently upgraded from a Ryzen 5600 to a 5700X3D and have been testing stability after undervolting (MSI B550A-PRO, latest BIOS 7C56vAJ1, KomboStrike 2, which is equivalent to a -20 negative curve on all cores). No overclocking—just undervolting for better temps and higher boost clocks.
So far, my system has been stable in Prime95 (small FFTs, blend), gaming, Cinebench, and most OCCT tests.
However, the latest OCCT Linpack 2021 test immediately triggers WHEA 19 errors on Core 0, while previous Linpack versions (2019, AMD64) do not.
I've tested RAM stability with Memtest86+ (Crucial Pro 32GB 3200MHz, XMP enabled) and verified the timings in CPU-Z—everything checks out.
Resetting the negative curve to 0 with PBO2 didn’t help; Linpack 2021 still fails within a minute, meaning the issue persists even at stock settings.
Reducing PPT from 142W to 100W eliminated errors. Some users suggested that Linpack 2021 forces AVX2, which might be the cause.
However, CoreCycler (configured with LINPACK2021 or Y-Cruncher with AVX2 enabled) and Prime95 AVX2 do not trigger WHEA errors, making OCCT Linpack 2021 the only test that fails.
Could this indicate a CPU defect, or is there another explanation? Any advice on further troubleshooting is appreciated.
Thanks.
