Quote:
Originally Posted by Unregistered
Code:
[Jan 26 18:47] Test 1, 460000 LucasLehmer iterations of M250519 using AMD K10 type0 FFT length 12K, Pass1=48, Pass2=256.
[Jan 26 18:47] ERROR: ILLEGAL SUMOUT
[Jan 26 18:47] Possible hardware failure, consult readme.txt file, restarting test.

Prime95 started the 12K FFT test and ran into a hardware problem. ILLEGAL SUMOUT is generally a floating point operation returning an invalid floating point value.
The 12K FFT (and 8K FFT) can put more stress on the FPU since the FFT data fits in the caches which reduces stress on main memory, but increasing stress on the FPU and caches.
Rerun the stress test, but choose small inplace FFT tests. You may be real close to 100% stable, but not quite.
It is possible you found a rare prime95 bug, but not real likely.