I have done some more tests, interesting ones I would say.

Well first I have to say that I tried to complete the Prime 95 test but it was not possible due to the high temperatures

That is the reason I keep it 4.2Ghz with 1.35V Hyper-Threading off.

First: Intel recommends it below 1.35, not to care nonetheless.
Second: Load times are 10 to 20c degrees less.

The first screenshot is at 4.2Ghz with 1.37,5 which finished 2 tests as Super PI 1M and 32M.



The second screenshot is the reason why I can't go ahead with this. I do respect 10%. An example is if the chips runs with a TJMax of 100c then the maximum I would let is 90c. This is far higher than my 10%, check the Realtemp program well. You will see it reached 100c and it was on the 3rd Prime 95 test 1024k which is a bit further than the beginning of the test.



The conclusion is simple and can see by anybody interested on the topic. If you need to use 8 threads with this speed at 4.2 using the best of the best aircolling solutions the Thermalright true copper 2 kilos then It would be better for you to go water cooling solutions as you will get a better voltage than me with 1.38V 8 threads hyper-threading on.

As for me I will stay with my 4.2Ghz at 1.35V 24/7 4 threads no problems. The reason is again very simple, it is cooler with 4 threads, less voltage, programs which I most use can not even use 4 threads let alone 8 threads.

I hope this helps,