GPU fan strange issues

[whiteknights]

i have sapphire HD 7870XT Dual-X. both fans was spinning in the first two years from buying the card. after that i started to notice that the second fan doesn't spin unless fan speed at 78% or above. i guess it happened after i installed Crimson driver. but that doesn't matter as i got used to it, and one fan seemed to handle the graphics card.

what is matter that after a couple more years and after i replaced my old thermaltake 450w PSU with FSP Hexa 500w, i've noticed that even the other fan doesn't spin at idle unless temps are above 42c (48c now). and the moment i stress the gpu with furmark or with a game it goes down instantly to 0 RPM (i don't know why?) until 78% then start to ramp up again with the other fan. suddenly from 0 RPM to 3000's RPMs!.

even with the fan curve set it to ramp before 78% it doesn't.. thats in gaming or stressing only, which is strange. i can ramp it up before 78% but with no stress on gpu. and it will turn itself off when temp is at late 30's or after a few minutes at idle.

also when watching an HD video through internet or opening VLC, the GPU fan usually doesn't spin unless i paused the video or close it and wait for a moment for the fan to start spin.. Temp can go above 75c while watching a video and after closing it the GPU suddenly realize that the card is hot and the fan starts.

i just need any explanation for why the moment i stress the gpu the other fan that used to work all times goes down to low RPMs until its 78%?.. and why it doesn't spin at idle unless temp is above 48, then when temp decreases to late 30's the fan turn off again, and so on..

i haven't installed any new third party programs before that happened and i haven't installed any new drivers.. the cause seems to be deeper than just "faulty fans". because if it just a dying fan it will act more randomly. but it seems that its being controlled by something. although this issue happens in the bios (fan spins for 1-2 seconds when i power up my pc, then after few minutes in bios it start for a while then stops again, and so on..

I'm sorry for the long post, but this problem is really making me frustrated. my curiosity to find explanation goes beyond my desire to fix the problem.
and I'm new here, so i hope you can forgive my long post.

 

[whiteknights]

anyone?

 

[EarthDog]

Pretty sure this was answered at TPU, no? Linus tech tips? Tom's? Bleeping computer? Super user? How many answers do you need? Are there additional question(s) from all the advice you received from other forums you have for us???

https://www.google.com/search?q=hav...e.&aqs=chrome..69i57&sourceid=chrome&ie=UTF-8

 

[whiteknights]

I'm sorry, but most answers was different. some said its a fan controller built in to gpu, other said its the gpu itself, some said try reloading GPU bios, other said its just a faulty fans.
that confused me a bit. so i thought i might have a deeper explanation here and some guide.

 

[S_I_N]

its the days of the internet and asking a question on 5 different forums and expecting a miracle answer. But in reality you ask on 5 different forums you'll get 10 different answers. None of which you seemed to of liked so your asking on yet another forum.

You need to put in the trouleshooting time and investigate it not just "well hey this is weird lets see what the forums think" How do you think we got to where we are we TROUBLESHOOTED things when they went funky and then after exhausting HOURS on it sometimes DAYS we then maybe asked on forums or googled it. Which btw wasnt what it is now a days.

 

[whiteknights]

that wasn't just 5 different forums, they were 8 forums plus couple of friends. troubleshooting myself is something certain that I'm going to do eventually, and I'm aware that there is no magic answer going to fix my problem without troubleshooting. BUT i prefer collecting all opinions and theories first before beginning, you may not like that but that is my method and it worked many times and made troubleshooting easier.

 

[S_I_N]

well my 5 was a generalization and I assure you most folks would like to see you try first ask second

 

[EarthDog]

Yes... you have had several suggestions across 8 forums. Its time to actually try some of them.