Thanks for the info.
Looks like Sapphire Pulse cooler is unable to cool down the memory chips under mining load, and the reference cooler does better job at it. Are you using custom fan speeds or left it on auto?
Also does The XT and non-XT performs the same regarding mining?
Non-XT is 0.5-0.8 Mh/s slower than XT given the same clock, etc. settings
I'm using MSI AB for fan curve, but it doesn't seem to be affecting it much (if it's even working). I had the fans up to 90%+ which might have cooled the core temp a little, but HBM temp remained the same.