Hello everyone.
 
I own an EVGA GTX 970 FTW and after three years i saw my temps rising from my custom fan profile's 74c max to 80c+ so i decided to replace the paste. I had a 3 year's old MX-4 which i used and imediately i saw a change to max 72-73c (i always measure temps using FF XV at places where VGA power and usage reach 100% to be sure it is the worst or close to worst scenario), but... after every 1-2 days i see my temps rising and after three weeks we are back to 80c+. I thought it was the old mx-4 or the way i applied  the paste (speading it evenly on all dye) so i got a new mx-4 package and redone everything using a huge rice dot and let the heatsink do the rest. After 3 weeks same thing.
Is MX-4 that bad with my card? I check the screws if they go loose but nope. Ambient temps are about the same. Do you have any thoughs what is going on?
 
Thanks for your time.

Thank you for your answer.
 
The problem is when temps reach 80c+ unless i unlink temp limit the clocks start to go down and of course fan noise start to become unbearable to my ears at 50%. Still i have the mystery why temps are ok when applying new paste and as days pass becomes worse. Next thing is to remove the card and shake it a bit to see if it has to do with heat pipes going bad and ordered Kryonaut paste to see if it makes any difference.

I also assume you have thoroughly cleaned the fan blades, and also the heatsink itself? Not sure if you live in a pet infested home, but man does it really dirty up the computers fast! Also being as it is summer, expect higher then usual temps across the board(unless well A/C room). Likely you have already taken these into account, but you never know  Hope it's not the GPU starting it's degradation process, but if I were you and you can't get a fix on it, i'd be looking into replacing the card. Best of luck Cos84!

Why not use Arctic Silver?
It lasts for a couple to a few years.
;)

Ok lets recap:

Card used: GTX 970 FTW (170W model which doesn't have thermal pads - ASIC Quality 67%)
System Specs: I7-5820k with Coolermaster Hyper 212 Evo (Temps never exceeded 60c while gaming when not OCing - Generally  i don't use OC while gaming), 32GB ram Quad Channel @ 2666Mhz, MB Asrock X99 extreme4 and case is Coolermaster N500 with two fans 12cm, one front, one back. The fan at the back is set at 50% speed and start rising when cpu temp exceed 50c. The front is set to off and start to spin from 30% when cpu temp exceed 50c. So generally when gaming or doing something both fans spin. Case is at least 1 meter above ground, 99% dust free.
 
Today Kryonaut thermal paste arrived. I removed the card, unscrew the 4 screws aroung the Gpu dye (Mx-4 was evenly placed across all dye using the rice dot method before), removed the old paste using 90% Isopropyl alcohol on kitchen paper, let it dry and used the Kryonaut paste with the rice dot method again. Then I used game FF XV on Vesperpool location where card hits power limit (98-101% power usage there with boost clock going from default 1380 to 1367mhz and back). Max Gpu temp on 25c room ambient temp with system uptime 2 hours: 75c. I used all 3 years i have my system MSI Afterburner for my info and custom gpu fan profile which starts at 20% fan speed on 60c, up to 50% fan speed if temps reach 79c (more aggressive than GPU's default).
 
So day one using Kryonaut temp looks totally ok (same as cards factory paste, about 1 degree higher than Mx-4 at day one). I will see if temps start to rise again as days pass. Both previous attemps with Mx-4 ended with temp reaching at least 80c and start to throttle due to high temps after about 3 weeks.

Yeap that's the card with 1 Display Port, ACX 2.0. As i said my profile is more aggressive than card's default (with default profile temps are 2-3c higher). At 50% fan speed the noise is just unbearable for me when not wearing headphones (even with headphones i can hear it a bit at that % ), it even covers almost all coil whine which is not minor. The PC case has grills for 2x12cm (i think) fans at cards height and most of the air goes directly out, as i have put my hand there and felt the air coming out from the card.

Hello again!
I am happy to announce that after 3 weeks using Kryonaut, my problem looks solved. Temperature remained like day one max 75c. Mx-4 failed twice to keep day one temps, so either it isn't good for Gpu applications or have some problem with mine .