reset bios and if it still happens, disable all the thermal control stuff.
Possibly look into windows power options and see if something still is going on in there.

Sounds like it could be GPU related too, just cos it works, doesn't mean there is not a looming problem.

Maybe try another card in, if it works then you know its GPU and time to sell it to second hand store like I never do.

Could be lots of tiny things you never fix without serious swap out, been really lucky with my PC's never really fail hardware wise.

I'll give the bios thing a try

I really hope I don't have to sell the card because I only just bought it.

If worst comes to worse and it's actually the card dying or fucking up, I'll contact gigabye directly and request a new card because fuck buying a new one when it's not even 6 months old.

"my pc's fans will go full speed"

I think you mean your GPU fan will go full speed. Can you confirm exactly which fans you are talking about? I am suprised if it is cpu fan also.

Let me guess this is an ATI 6950 or something very similar?

How many PCIE power connectors does the card use, one or two?

I have two 6950's that do this.

The first one does it the moment i turn on the PC

The second one is ok, A couple of times the second one did the same and I discovered both of the PCIE power connectors were not inserted corectly because they overlap each other and I had inserted them in the wrong order.

Considering your computer works for awhile id say you have them inserted correctly anyway.

So this is the standard response of an 6950 (and maybe other cards) to go max rpm when they are not getting their PCIE power.

I would say it might be the psu, but more than likely something is dying within the voltage regulation part of the videocard.

You want to be careful with that PSU in future but more than likely it is the videocard.

Best option is going to be trying a new card in that computer or pairing the current card with a different psu or computer to see what is really broken.

If you go for a new card go for something low power like a gtx960 or 1060.

Edit: Maybe I should add I did have your exact problem - I was watching a movie in perfect silence then suddenly bang the 6950 hit max rpm....It only got worse next few days to point where it would happen as soon as the pc was turned on - I tested it in multiple psu/motherboard and it kept its problem - only later with the second card I started to doubt myself that maybe I had never been plugging in its two power connector correctly - but I doubt it was that because I tried it like 10 times.

Edit2: Also it was not just the fan going max rpm because I disconnected the fan and ran it over to the 5v rail - yet the card is still unstable and commonly freeze/crash the whole computer.

Edit3: You want to check on the PCIE power connectors also - funny enough I have a vague memory of switching the two power connectors back and forth between the two plugs on the card yet now I think about it its is keyed and has little clips to show they only go in one correct way - yet it seems possible to put them in the wrong way and the computer might even boot that way - so check they are in correctly with the different shaped pins and little notches that make one plug sit above the other.

Might be the gpu fan, next time it happens I'll check

It's also not an ati card, it's an nvidia gtx 1080

If it's the card I'm pretty pissed since this is a relatively new card, I bought it about 6 months ago.

That is such an expensive card.

You just want to test it on another PSU

If you dont know anybody with a 600w psu to test it take it to a local computer shop and offer them $20 to see what it does in a different system - if they want more then this just find another shop (unless it takes hours for the problem to kick in then $20 might not be worth their time)

The problem being is, even if it is indeed the psu, testing it out at a computer shop is kind of redundant since my computer shuts down at random, so it could potentially take days or mere hours, it's very inconsistant.

Next time it happens, I'll check if it is indeed the GPU fans, if it is, I'll disconnect the card, connect it up again, making sure it's connected properly and if it happens again I'm pretty sure it's psu related.

Thanks for the help anyways I appreciate it. What I think I'll do is buy another PSU since they're dirt cheap anyways just to be sure.

what if the temperature isn't being measured properly and it's actually 328 degrees

that or you've got hidden bit mining program running in background

In my case nope and nope

It isnt temperature because it goes from 500rpm to 5000rpm in the space of less than a second - not a gradual heat up as you would expect

It isnt a virus because I was using it in a media pc that had never touched the internet - and it does it on another mobo/os and it also does it under linux and at the bios screens.

Take ur videocard and unplug the pcie power and see what happens. If its an older Radeon it will go max rpm. An older nvidia will usually display a red light and start beeping if it has an onboard beeper speaker but it really depends on each card what it will do.

I've used two third party programs, trust me it ain't overheating :D plus my case is one of the best cases for airflow you can get

https://www.corsair.com/uk/en/Categories/Prod...9011096-WW

I made damn sure my stuff wasn't going to exceed over 60c

Psu failures usually result in reboot and happen under high load.

This sounds like a gpu problem (connections / voltage).

Don't buy nvidia, problem solved.

Honestly, I've never had a single issue with nvidia stuff ever until now so can't say it's Nvidia.

check the cable.
no one ever checks the cable.

probably a broken wire in your monitor cable, if you crushed it with your chair, or its just cheap and not oxygen free they die after a few years

yes because a broken monitor cable would really affect fan speed.....
That's like saying, if you have a Flat Tyre, check if you have not run out of petrol.

think p0rt think!

im thinking https://en.wikipedia.org/wiki/Signal_reflection

In which case I'll go with a rogue, russian nucelar bomb set off in sibera, and the emp could have disrupted it.

Help me p0rt, you're my only hope

Touch wood, I took out the graphics card, unplugged all the shit, replugged it, made sure it was properly secured and im not getting any resets so far.