Row Refresh Cycle Time : 55
Vcore : 1.4
NB voltage : 1.28

If like you said system gets well into windows but fails on a core in small FFT's it's usually Vcore... you can also try to drop down to 7x and see if you can get 475 stable with above settings... make sure ya ram stays in sync !!!
How hot does that CPU run with ya Freezer ?