I have a Ryzen 5800x that I replaced the thermal paste with Arctic MX4 about 5 months ago. Back then it took about 25 seconds for the CPU package temperature to reach 90C and my Cinebench scores were higher. Now the CPU package temperature hit's 90C instantly and I'm experiencing more thermal throttling that before. 5 months ago when I replaced the thermal paste (Corsair XTM50) with new thermal paste (Arctic MX4) an it would score in upper 5900's to low 6000's in CB20. Then months passed and I was experiencing more throttling and CB20 scores now reach low 5800's to mid 5900's. Could it be the weight of the heatsink/fan assembly of my Noctua U12A overtime loosening up the contact with the CPU. I'm using one of the best thermal pastes around, so it can't be the thermal paste quality. I used the X-method, but I didn't find any difference in thermal paste application method for the nearly 2 years that I owned this CPU. If it's a weight issue (gravity pulling the heatsink downward), would an AIO be the solution to this issue? My case cooling is 2x120mm intakes and 1x120mm outake, but I also tried 2x140mm intakes and 1x120mm outake and my CPU actually ran hotter with the 2x140mm intakes than the 2x120mm intakes. I'm using a Fractal Meshify C case.