I bought a used RTX 3070 Ti Founders Edition because my previous graphics card was getting old. It was already reaching around 89°C, so I replaced the thermal interface material with Thermal Grizzly PTM and installed 1.5 mm Arctic TP-4 pads. After disassembling and reassembling the card about five times, using up the PTM and later trying MX-6 paste, the temperatures have barely changed. I've been careful to use the correct mounting pressure each time. During an OCCT stress test, the GPU core sits around 86°C, the hotspot fluctuates between 98–99°C, and VRAM reaches about 82°C. The GPU clock varies between roughly 1725 and 1740 MHz, memory stays at 1187.75 MHz, and the fans run near 2800 RPM. Could the replacement pads be too thick and preventing the cooler from making proper contact with the GPU core?
2 Answers
This sounds more like a cooler-mounting issue than a bad paste. On these cards, getting the pad thickness and compression right can be surprisingly difficult. Thermal putty on the memory and other components is often easier because it fills the gaps without forcing the heatsink away from the GPU die, while regular paste or PTM can be used on the core. Also inspect the contact pattern after tightening: an uneven or incomplete imprint is a strong sign that the pads are too thick.
The 1.5 mm VRAM pads may be causing the problem. If they’re thicker or less compressible than the original pads, they can hold the cooler slightly away from the GPU die. That gives the memory good contact but leaves a small gap over the core, which leads to high core and hotspot temperatures and very high fan speed. I’d try returning to the original VRAM pads if they’re still usable, or use a thinner, more compressible material rather than relying on mounting pressure alone.
That makes sense. I’ll try replacing the 1.5 mm pads with 1 mm ones and check whether the cooler is making a better imprint over the core.
I’m starting to think the pad thickness is the main issue. I’ll test the contact pattern and consider thermal putty if thinner pads don’t solve it.