I had the same problem with my Asrock PG 7900xtx, high delta between core and hotspot. Hotspot was above 100 in no time. After repasting and torquing it down with .4nm, problem solved(still way to hot though). Since the rest of the system was watercooled i bought a Alphacool Core block for Asrock since EK was no go for Asrock. It took a bit finding right torque values, i used .4nm again for the GPU core and .3 for the million other tiny screws. Now it is hotspot 70-80 degrees at full load(450watt with 3100Mhz) with 58 on the core(2x360 and 1x240radx54mm. I find that it is extremely important to check pad thickness and correct placement and then use a torque driver. I also torqued it progressivly .1 to .2 to .3nm etc. My only gripe with Alphacool is the restrictive flow, small diameter inlets on there blocks. I went from 250 L/H to 150 L/H, however perfomance is top notch.
Oh, and do put support under waterblock, i do not think Alphacool ever put their blocks on a scale before they sell them. It weighs a ton.
Oh, and do put support under waterblock, i do not think Alphacool ever put their blocks on a scale before they sell them. It weighs a ton.