I installed PTM7950 on my hybrid 3080ti. Please note that I also have a copper plate mod, so my vrms are getting cooled by the radiator vice the vrm fan.
So far temps are GREAT. On 3dmark time spy, with a fresh MX4 paste and push/pull with noctua redux p12-1700 I used to get 54C (I know there are better tests, but for comparison wise I always use that). Over time it gotten worse and with recent tests I would get 66-68C on 100% rad fans, vrm fan and case fan (yes it's louddddd). In gaming (cs2), I would start in the 62-ish C and finish my night in a warm room at 72C, with 50% case fans, 60% rad fans and 35% vrm fan.
With PTM7950 so far:
1. 3dmark time spy: 54C with push ONLY with noctua A12x25 at 60% rad fans, 35% VRM (I could turn it off completely but I would still like some airflow in there)
2. Gaming: same fan speed as above (nice and quiet!), under 60C no matter what. Even if my room got warmer, I would fluctuate between 52-58/59.
3. Furmark: for some burn in, I left regular fan speed as above, and I would be maxed out at 58/59C same as gaming. I did turn down the rad fans to 35/40% and I was getting 66-68C max.
Overall super happy. I think it's the same temps or better with a fresh thermal paste, BUT I'm using only 2 rad fans instead of 4. I was getting annoyed with the very loud PC that I started looking at quiet options (obviously gotta throw noctua a12x25 in there!). Now I'll never need to re-paste again and temps should stay pretty consistent.
Temps are above 45C, so a phase change should occur. I also have a hotspot that is in the 60s, and VRM that although not touching the ptm7950, it is getting heat to the pump plate. Pump plate should be above 45C, so I see the PTM7950 working as intended. And if it doesn't, I mean whatever, it's efficient enough to give me low, consistent temperatures.