What is happening the cores hit 120C very fast and then either turn off or get the frequency turned down so it runs slower at a cooler temp.
If you want to see the fast error just connect the board to a PC with usb and run cgminer. It will show which cores are getting hot.
Regarding the ring around the cores, what would happen if that was ground down well below the chip height? Anyone tried this?
Has anyone tried immersion cooling these boards or has everyone just thrown them away?
Thanks. I'll try that out. I don't think it's hitting 120 though because it seems to top out around 95 as best I can see. It could be the UI isn't keeping up though. I really don't like the cointerra UI. I have a couple pi's and a failing controller now so I may swap the failing beaglebone with a pi and see what happens.
With regard to the spacer I ground mine down to even but not below. I checked the pattern of the thermal paste after doing so and there was a significant difference in the contact pattern of the block against the chips. Before I had visible high spots in the paste but after grinding the spacer things were much more even. After running for a couple days I think this change yielded 10-15C improvement.
I am planning on either removing it with a razor or grinding it down further the next time I have them apart (probably this weekend). I will post results for everyone with pics.
So far with the changes I have made one board has dropped an average of 40C and the other 60C and that's on noctua thermal paste. I still have some work to do because I am only running at power level 6 and cannot run higher at this time without the boards exceeding 80C.