I’ve read good things about PTM7950 and decided to give it a try on two builds:
- 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.
- 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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AMD and custom AIB should use PTM7950 or something better on current gen or nextgen, or least something that does not pumpout and AMD should adress the pumpout issue either by adressing the flatness of their dies if realistic or by better thermal interface material that no longer pumps out.
NVIDIA uses it on their 4090 FE as well so this might be new reality with more power going thru small chips and might be not be simple fix of making dies more flat as they aren’t always perfectly flat anyway, however AMD chips are usually a bulge, while i heard that NVIDIA are usually more a concave, the later is more vulnerable technically to to much mounting pressure on the edge, while AMD is more vulnerable to at center of the die.
Something i also do not understand is why they do not do a mounting presure test to use the perfect thickness thermal pads on vrm and memory chips etc, some custom AIB use way to thick pads i understood.
Pads are supose to compress as long they do thickness should be fine even if slightly less thick.
Having a watercooled 7900 XTX should not have 95+ hotspot ever no higher then 70c hotspot at 410w tbp at 22-23c watertemp which translates in 21-22c room temp if you have external watercooling like a mo-ra3 420
I suspect with your 6700 XT the new thermal pads are causing the high delta due to mounting pressure error.
Nice results!
I was so impressed with PTM7950 on my XFX 7900 XT, that I applied it to a decade-old Lenovo Y580 laptop. The CPU/GPU temps dropped by a whopping 15/25°C, respectively. Disassembling and dust removal probably helped with the overall cooling, as well. Now it doesn’t sound like a leaf blower under load :)
Thanks for sharing your experience and for the detailed review!
Mx6 pumps out within a couple weeks as well. I tried that on my 7900xtx. Immediately switched to a ptm7950. Amazing results. My hotspot is cooler now with a +15% power limit than it was with a -10% limit with mx6
Where did you purchase your ptm7950 from?
I got it on Amazon from seller JOYJOM
Same for me, I made switch few days ago. Hoping for similar results even after few months
Ptm rules, converted entire household to it.
You’re behind. I replaced my shoe insoles with it. Made me run 2.5 mph faster. 💨
You joke, but…
Nice results especially on that 6700 XT!
My 6800 XT Gaming X Trio has a 30-35c delta. In games like Alan Wake 2 and Cyberpunk the avg core temp reported bounces between 70-72c but the hotspot will be 100-105c. This is with a reported power draw in Adrenalin of 280w. Had the card for around 2.5 years now and never repasted. The temps have always been high. Seriously considering a swap to PTM7950 to bring that delta down so the gpu fans don’t keep ramping up to 2200rpm and maybe I could increase power limit to overclock a bit further
Thanks for making this post
MSI has always treated AMD GPUs as second class. I have bought a RX480 GamingX for my brother in law (a while ago) and the cooler is basically the same cooler for the Nvidia GPUs. Nothing specific for the AMD GPU and when I opened the cooler I noticed some things were really being correctly cooled.
The GPU is still working and with decent temps, but already had to repaste 2x and had to buy new set of fans as the older started to make noise.
What dimensions did you need for the 6700 xt?
None of these have had any real effect, and the GPU would hit 67C and the hot spot 102C.
That doesn’t seem normal.
I got the Sapphire Pulse model and after repasting with Gelid gc-extreme the hotspot doesn’t go above 100°C with default settings or above 90°C with undervolt and custom fan curve (it usually hovers at 75-80°C). The temperature delta is never more than 10-15°C. I also changed the stock thermal pads with thermal grizzly minus 8 (1 mm on vrm and 2,5 mm on vram).
Before this I had Noctua NT-H1 and stock thermal pads, which resulted in hotspot temperatures above 105°C when undervolted or 115°C when I used default settings. Also the temperature delta was 30-50°C.
What would be the results in a year? I read that in the long term paste still wins.
Not sure where you read that but it’s 100% wrong, thermal paste gets worse with time, whereas the PTM7950 datasheet shows it actually improved after 1000 cycles of -55C to 125C.
PTM7950 is an industrial product used in things like power modules/inverters , High powered LEDs, where it needs to last for the lifetime of the product.
Where can I buy PTM7950 and how much it cost also what sizes it comes
You should replace thermal pads with thermal putty while you’re at it.
Thanks. I see some details in another reply and will definitely try some.
could you compare the PTM7950 thermal pad with the Thermal Grizzly Kryosheet Thermal pad if possible?
I do use the Kryrosheet on my CPU… it’s awesome