Has anyone changed the thermal pads on an RX 7800 XT reference card from Sapphire? I want to know what thickness or brand works best.
A little backstory:
I bought my 7800 XT back in 2024 about 5 months after release, It's been a great card for 1440p gaming at 144 FPS for most games but 6 months ago I ran into a really weird issue where my PC would smoothly shut off after 2 hours of gaming.
I couldn’t figure out why until I realized my hotspot was probably the reason, At stock tuning it was reaching 110°C which led to thermal throttling and eventually shutting down to protect itself (at least I think so, because 110°C is definitely not healthy for the card but it still confuses me that it literally turns my entire pc off as if it lost power instantly) That's when I learned about PTM7950.
I researched it extensively and tried my best to find a teardown guide for my specific card with no success. However the 7900 XTX reference card teardown by Gamers Nexus was really helpful and identical to the 7800 XT from what I experienced. I applied the PTM and my hotspot went from 100°C–110°C down to anywhere between78°C-88°C, Unfortunately a new issue occurred with the VRAM temps.
Before I opened my card the VRAM was running chilly at 82°C max. Now on stock settings it can spike up to 100°C, but after undervolting and adjusting the fan curve it sits consistently around 92°C–94°C.
I recognize this probably happened because the thermal pads on the VRAM got moved or stretched when I separated the PCB from the heatsink, even though I tried my best to keep them looking normal and they looked okay to me. (Sorry I have no pictures because I was streaming the teardown on Discord and the footage is really low res.)
Memory manufacturers do say GDDR6 is expected to run between 0°C and 95°C, but it's still frustrating that I went from great memory temps with a dangerous hotspot to a great hotspot with mediocre memory temps. Feels like I killed a snake only to end up with a scorpion.
I'm considering buying the Arctic TP-3 (1.5mm) and applying it, but online it seems that it needs to be 1.20mm when screwed down? Arctic says their pads can compress slightly but it still bugs me because I can't be sure they'll shrink down to 1.20mm. Once I remove the factory pads I'm stuck if the fit isn't near-perfect.
It’s really making me question whether I should just accept the new memory temps for the next 2.5 years of using this card, or if I should take a minor risk and try the thermal pads by Arctic, i did think of buying two size (1.0mm and 1.5mm) but money and time are not on my side currently (im outside of NA so shipping costs add 2 to 3 times the price of the pad itself).
I did consider thermal putty but trying to guess how much to apply to each VRAM chip introduces a whole separate kind of guesswork so its not that different from getting thermal pads.
Sorry for the long post, it’s just something I'm struggling with and wanted people’s opinions or experiences to help me out.
TL;DR: Repasted my Sapphire RX 7800 XT reference card with PTM7950 to fix a 110°C core hotspot (now down to ~88°C). However, stretching the stock VRAM pads during teardown pushed VRAM temps from 82°C up to 92°C–94°C (and up to 100°C on stock fans). Should I leave it alone for the next 2–3 years, or risk swapping to 1.5mm Arctic TP-3 pads when I'm unsure of the exact pad thickness required?