Okay, so originally a month after I got my GTX 780 I replaced the thermal paste with some Gelid GC-Extreme. About a year later I started noticing much highers temps. After trying many other things, I took the cooler off to inspect it. To my surprise an entire corner of the die no longer had any TIM on it. I found this strange but went ahead and reapplied the TIM. Temps immediately went back down. A few months later, again I'm noticing much higher GPU temps suddenly. I angrily remove the cooler and once again am presented with the same missing corner of TIM. This time I took pictures, here are pictures of the die and the cooler: I don't know what is going on. If you look at the pictures, you can see there is some overlap on the corner that is now bare, so there definitely was coverage there when I first applied the TIM. Could I have a defective tube of TIM? I've used the same tube on my CPU and never had any issues. I went ahead and applied some more on it again and the temps are back down. I tried a different method this time, I had been using an X method and I switched to a dot this time. I'm really concerned this is going to keep happening. Not only do the temps go way up when this happens but I also start to get crashes as well. EDIT: I forgot to mention, this is the EVGA ACX 2.0 cooler
Hmmm I can only try to guess what's the problem there, but of course a troublesome leftover of TIM could be the reason, if it was open already and used on the CPU before. Then again, I've read that GC-Extreme was rather complicated to apply, changing it's consistency with temperature (not sure if it wasn't more like it got 'harder' with rising temperature). Maybe there's some odd physical thing happening to it under load (temperature) that makes it 'shrink' some how, althought that too would point towards a TIM that does not behave like it should. The most direct (and to me logical thing) would be to check if both surfaces are flat and parallel, or if maybe the heatsink was pressed to the GPU a little stronger around that corner, thus pressing the TIM out once it became warm and a less resistant to physical pressure.
What is the little spot near the lower left of where the TIM should have been? Is that a tiny raised bump?
If I was to take it back apart and put a different type of TIM on it what would you recommend? I was thinking either PK-3 or MX-4 or even some Tuniq TX-4. I have some Noctua NT-H1 that came with my NH-D15 cooler but in the charts I've seen, the Noctua paste doesn't do too well on GPUs.
It does appear to be a slight imperfection of the surface of the cooler. That scratch on there was not caused by me it has always been there. The picture I believe makes that little tiny speck seem a lot bigger than it is tho. It was so small I never even noticed it until I carefully inspected the photo. Also I'm not sure it's even raised, there appears to be some sort of outer coating on the heatsink.
I use MX-4 or Ceramique, depending on which I have on hand at the time. Both work very well on GPU's.
Agreed, Ceramique is probably the safest you can use on a GPU as well. Its completely non-conductive and non-capacitive, so if you use too much and it bleeds out on a nearby capacitor you don't have to worry. From that pic it looks almost like the dry corner of the heatsink could have been tightened down a bit more. It could also be runny TIM material that migrated out over time. If you know for certain that the paste is getting spread out over the die properly, then its probably bad batch of paste that is running and leaving a dry area after a while.
PK-3, gelid gc extreme, MX-4 are good to use. Never had issues with GC extreme, so think its either a bad batch or the cooler isnt flat, so when it heats up the tim gradually moves towards the center of the die
NT-H1 is my favorite for both CPU/GPU, easy, lasting, performing. (takes few heating cycles to kick in fully) Idle 35C, heavy load 63C. And that little dot at heatsink, you should be able to feel by touch if it is hole or bump.
Well the last times I used the NT-H1 too, and to my personal feeling, I never had problems with it. Although reviews say it's not the best performing, it's easy to apply.
You can look at the TIM pattern and tell that the cooler isn't flat. If that were the cooler off one of my cards, I'd be throwing it in the trash and replacing it with something of better quality.
I did contact EVGA, they won't send me a new cooler or even let me buy one. My only option would be to RMA the entire card. I would prefer not to RMA the card as I'm sure I would be getting a refurbished one in return. Even if I do RMA, I would either have to be without my card for a few weeks or pony up $500 in collateral for a cross-ship. Okay, so a little update; got the PK-3 today. With the Gelid GC-Extreme I would get 66C doing one benchmark of Unigine Valley (64-65F ambient). Cleaned the old paste off (imprint looked good) and applied the PK-3. I applied about a pea sized dot which I knew was a little too much but was hoping it would help stop this from happening again. Ran the benchmark with the PK-3 and it hit 69C. Wasn't real happy with this and I figured it was because I put too much. Took it back apart and I was right, too much. Cleaned it off again and applied an amount in between a pea size and a grain of rice size. This time the temps just barely hit 66C matching the Gelid paste. I'm really hoping this will fix things. Funny (not at the time) little story that happened when putting the card back together the second time. I always screw the screws in, in an X pattern which requires you to screw it down a few turns to get it started at first. Apparently I didn't screw it down far enough and while I was getting the opposite corner started, the screw and spring when flying off and landed halfway across the room. Got really lucky and saw which direction it flew off so I was able to find it after a few minutes of searching.
That's the thing though, every time I've applied the TIM and then taken the GPU back apart right afterwards, the pattern looks great, it's clearing covering the entire die. Replacing the cooler isn't really an option, the only aftermarket coolers really out there for GPU's are the Acceleros and the new model of those are getting horrible reviews after they ditched the VRM heatsinks.
That little scratch looks more like a valley to me, TIM only missing on that corner where the valley is. Maybe the TIM is drying up on that corner because it releases the fluid from it there. TBH though what a mess, hope to god you only use none conductive paste or you'd be screwed looking at those photos. Bottom and right side are all contacted if that paste is conductive.
Non conductive paste, I would never use conductive paste on a GPU. Also, I actually believe what you are seeing on the pins is leftover from the stock paste, I just didn't bother to get rid of all of that as it has no effect.