7970M is going from 60 to 100 C within a few seconds during gaming

So I just recently baked my GPU back to life and I wanted to test how it gamed with Dark Souls: Remastered. The game runs ok for a few seconds but over the course of about 5-10 seconds with the GPU at 90%+ usage and full clocks, the core starts heating up rapidly from 60C to 100C. At 100C the GPU throttles down significantly, taking FPS down to a fourth of what I was getting at full clocks. I'm pretty sure I've never had this issue before, as in instant thermal throttling.

For an idea about my setup, right now I'm waiting on replacement screws for the VRAM heatsink. Only the left screw hole is tightened while the right has no screw. The heatsink for the core is there but there's probably some gelid thermal paste buildup underneath the black tape that surrounds the main die. Maybe that has something to do with it? Or maybe I've applied too much thermal paste? Maybe the paste still needs to cure or something?

The other thing I'm concerned about is that while I was cleaning off the heatspreader I tried scraping this little white spec in the top right quadrant that wouldn't come off and was what I assumed to be a temperature sensor. Maybe I damaged it by trying to scrape it off? What is that thing for?

And maybe the GPU isn't functioning properly after baking it?

The rapid increase to 100c is what doesn't seem right to me. Something is truly wrong but I'm not sure what it is.

 

Sounds like the GPU heatsink isnt secure, generally that is the case when temps skyrocket like that.

 

What do you mean by not secure? I'm even using my extra tight screws (with added washers) for the core heatsink. Should I not be afraid to go as tight as I possibly can? Or did you mean something else?

 

You mentioned missing screws in your OP.

Otherwise it seems you need to resecure the card and repaste.

I just baked my card yesterday, now my load temps are around 55C and idle temps 29C

 

The screws are missing for the VRAM heatsink only. Baking helped your temps or did your GPU die?

edit: just took off the core heatsink and it isn't looking right. The paste wasn't spreading to all corners, so either it wasn't tight enough or the buildup under the black tape is keeping the heatsink from properly pressuring the GPU die. Maybe if I put too much thermal paste it prevents the heatsink from being able to make a thin enough layer, because there's still way too much at the center on both the heatspreader and pressure plate. I'm gonna clean under the black, might need to cut it open actually.

edit 2: I'm learning many lessons from the past few days. After peeling off the black tape around the GPU core, some capacitors (or resistors?) were pulled along with it. Must have been the issue that baking fixed? There's no way for my to get the components back on because its all surface mount and the things are tiny, and I need a heat gun. I tried the laptop for a bit as is and the 7970M wasn't recognized. Then I put the tape back on with some of the old components still stuck on (but with a couple others I know didn't go back inside because I have them sitting on my desk), repasted and really tightened hard the heatsink screws. Now the 7970M is recognized again...with several components around the die missing. Well then...so I've learned the possible cause of my GPU dying, and that I shouldn't ever remove that tape unless I really need to (there wasn't much thermal paste underneath anyway), and that a GPU can work without several of its original surface mount components. Maybe AMD implements redundancy so that if some fail the circuit can still provide proper power to the main components. Not sure. This ride is just getting more and more insane.

edit 3: And what do you know; Dark Souls: Remastered running at highest clocks at 70-80C! Not sure why it's running at 60% load now...will try to figure that out. After the DC jack drilling and now this I can't believe I keep getting away with it.

 

It could be the main heatsink has warped too, how does it look by eye?

But those passives are usually pretty important, the tape may be keeping them back in place via pressure.

 

It didn't looked warped to me. Still having some issues with heat but it's not nearly as bad now.

 

It could be that the core is getting over volted now the passives are missing, they are most at risk with baking.

 

At max clocks my 7970M is showing 1.05v in hwinfo, and .9v at idle clocks. Can or should I try undervolting? What are those "passives" on the PCB anyway? Just resistors right?

Heat was an issue earlier because I had it on a blanket in bed, plus weather has been hot lately. After I put the laptop on a hard surface with room for good air flow, temps are stable between 70C and 75C. So I'm pretty sure it's just when airflow is poor, temperatures continue building up to 100C.

 

You can have tiny inductors and capictors too. Estimated voltage from the controller means nothing if the delivery has been impacted.