Sounds like 1.28v was not sufficient for your settings.
Start with default settings and run a stress test.
I like OCCT, it will shut down your test if temperatures reach 85c.
Monitor vcore and the multiplier with CPU-Z.
Gradually raise the multiplier for all cores from the default of 42 to a higher number and see how you do.
Stop when you reach your max and back off a notch.
Yes, you can do more sophisticated tweaking, but this works.
The processor will slow down or shut off if it detects a dangerous temperature.
That is around 100c.
When all is done, implement speedstep and adaptive voltage.
That will reduce the vcore and multiplier when there is little to do.
AVX instructions are not common in most apps, but they are used in...