Hello,
Found this place after acquiring an Eisblock for reference 7900XTX off ebay and struggling with it and I would like to share my findings. First some caveats:
I'm installing this on the Yeston Sakura Sugar card. It isn't documented anywhere but since all the holes line up I can only assume it is using the reference board design.
This card runs aims for a 350W power target.
The Eisblock came from ebay without the 3mm pads for the backplate.
This is my first time ever attempting water cooling.
Initial install was abysmal. I spread my paste evenly as recommended by many and tightened all screws until they stopped against the board. I did not install the backplate since I didn't have pads. Average temps in the 50s and hotspot on the GCD was pegged at 110C in Furmark.
I noticed the bending in the board and backed off all the screws until it was flat against a ruler. This was marginally better, with the GCD hovering around 100C and bouncing off 110C and average temps in the 50s.
After finding reading through this thread I attempted to stack cheap thermal pads against the back of the core and installed the backplate. This was marginally better yet with the GCD hovering in the mid 90s, but still spiking to 105C occasionally. Others have noted that their cards maintain full boost clock at those temps, but this Yeston card seems to start throttling earlier and I could only maintain about 1500mHz in Furmark.
I took the whole thing apart one more time. I reapplied paste and this time just by laying dots on the MCDs and a fat log across the GCD. I reinstalled it using the spring bracket from the original air cooler that goes across the back of the core but with the eisblock screws. Tightened the screws until the bracket was touching the board on all four corners. Did not install the eisblock backplate.
Computer didn't post. Debug light for VGA problem. Sweating, backed off the four bracket screws by one full turn.
Computer boots, card now has an average temp in the mid 60s and a hotspot of about 85C. Raising the power limit to 380W It will now max the hotspot at 90C. Maintains ~2000mHz in the furmark test at these temperatures.
tl;dr, the eisblock for the 7900XTX reference is unable to apply sufficient pressure on the core. Attempting to tighten the four main screws further risks damage to the card. The 1Nm torque recommendation for those screws is absurd. Just use the spring bracket from your air cooler.
