hotspot delta improved from ~25°C to ~10°C after NT-H2 repaste
I have an RTX 3080 GPU from a Dell Alienware R11 that I purchased in May of 2022 to see what all the fuss was about, that I've had to put into service in a new build since I had to send off my new ASUS Prime Radeon™ RX 9070 XT White OC Edition 16GB GDDR6 for RMA since, when tested with OCCT found that the VRAM was defective.
Anyway, have been tinkering with the RTX 3080 and noticed that my hot spot temp was about 25C above my GPU temp. I disassembled my NVIDIA RTX 3080 to correct a GPU core thermal contact issue caused by dried-out factory thermal paste. Before the repaste, the card showed a clear hotspot problem under load: the GPU core was running approximately 72–75°C, while the GPU hotspot was reaching approximately 97–100°C. That produced a core-to-hotspot delta of roughly 25°C, which strongly suggested poor die-to-cooler contact rather than a general case-airflow problem. At that stage, memory junction temperature was approximately 78–80°C, so the most obvious thermal defect was the GPU core interface, not the memory pads.
After removing the card from the system, I carefully disassembled the cooler from the PCB, keeping track of screw locations, fan/RGB connectors, and the existing thermal pad locations. The original thermal paste on the GPU die was dry and no longer provided good contact with the cooler's cold plate. I cleaned the GPU die and heatsink contact surface with isopropyl alcohol, then applied fresh Noctua NT-H2 thermal paste. During reassembly, I tightened the cooler evenly in a cross pattern to restore consistent mounting pressure across the die.
The repaste produced a major improvement. After reassembly, the GPU core-to-hotspot delta dropped from roughly 25°C before the work to about 10°C afterward. One post-repaste test showed the GPU core at approximately 59.8°C average / 60.8°C peak, the hotspot at approximately 69.8°C average / 70.7°C peak, and memory junction temperature holding around 87–88°C steady with a brief peak near 90°C. Another sustained-load result showed approximately 65.0°C GPU core average, 75.0°C hotspot average, and a continued hotspot delta of about 10°C.
The memory junction temperature did not improve in the same way as the GPU core because the repaste primarily addressed the die-to-cold-plate interface. Later tests showed memory junction temperatures ranging from about 80–84°C in the better airflow run to about 94–96°C under heavier sustained load. That indicates the memory pads were still functioning, but the memory side remained more dependent on pad contact, case airflow, and sustained load conditions than the GPU core repaste itself.
Overall, the repaste was successful. It corrected the dried-paste issue, reduced the hotspot delta from an unhealthy ~25°C to a strong ~10°C, lowered GPU core and hotspot temperatures significantly, and made the RTX 3080’s thermal behavior much more stable and predictable. Memory junction temperature remained within a workable range, so the paste replacement solved the main problem without immediately requiring thermal pad replacement.