I’ve read good things about PTM7950 and decided to give it a try on two builds:

1. XFX SPEEDSTER MERC319 AMD Radeon RX 6900 XT LIMITED BLACK (crazy name for the XTXH version) with a 7800X3D, ASRock X670E Taichi, 420mm Arctic LF II, Phanteks Enthoo Pro II, etc.
2. XFX SPEEDSTER SWFT309 AMD Radeon RX 6700 XT with a 5900X, ASRock B550 Taichi, Noctua NH-D15, Corsair 5000D Airflow, etc.

All tests are with the OCCT Power Stability Test, run for 15 minutes, which seems to be enough to get to a plateau. The ambient temperature varied by 1-2C for all of the runs.

The 6900 XT has been in regular use for ~14 months and has never really run hot, even when OC’ed for benchmarks. With the stock tuning the GPU hits 73C and the hot spot hits 86C. I often undervolt it, where it maxes at 68C and 84C, respectively. I consider myself lucky as I’ve seen posts where other 6900 XT owners reported much higher temps, even from makes/models that are supposed to have better coolers than XFX.

Taking the 6900 XT apart wasn’t much different than other GPUs, and like all of them it can be a challenge the first time trying to figure out all of the screws. The stock paste looked pretty rough, with that “pump out” appearance, but it must have still been working well. Applying the PTM7950 is a bit nerve-wracking as it is fairly fragile, and my recently trimmed nails made grabbing the thin protective cover a pain.

After getting it all back together and reinstalled, I ran OCCT once to prime things a bit, then let it cool down for the main run. The results were good, with the GPU hitting 61C and the hot spot 81C. A small improvement, the results in games are even better.

The 6700 XT hasn’t seen as much use in ~19 months, but has always run hot. I’ve tried it in different cases, with different amounts of airflow from case fans, and various thermal pastes. The latest paste is Arctic MX-6, and it’s also had MX-5, MX-4, Thermal Grizzly Kryonaut, and stock. The stock pads were replaced with Gelid 12W. None of these have had any real effect, and the GPU would hit 67C and the hot spot 102C.

I’ve repasted the 6700 XT several times, so this was easy, except for trying to grab the protective film. I was hopeful that there would be an improvement, but it was better than expected. The CPU now hits 62C, and the hot spot 85C. Some might point out that the delta is greater than the 20C often suggested, but I’m pleased with the hot spot coming down to what feels like a better range. I need to try some benchmarks and games to see how it does, but my expect it will be better than before.

I have no affiliation with Honeywell, who makes PTM7950, the vendor I bought the kit from on Amazon, or Amazon. Hopefully this might inspire others who have hot-running GPUs to give PTM7950 a try. It is more expensive than a tube of MX-6, but I’m guessing this will last for a while.

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