Hi guys i recently bought an second hand rx 580 the msi armor edition oc and the thing is at 100% fan speed is nearly at 3500rpm and its too noisy also the temps stay at 76-78 degrees all time (40 at idle with 0rpm). What should i do? I was plannig to buy an custom arctic coooler they are a bit too expensive. Thanks
Take the side panel off your case. If the problem goes away then you need to look at improving your case cooling situation. If it doesn't, then you probably have a problem with the graphics card and it either needs to have the thermal interface material (paste) replaced under the heatsink or there is a driver or fan issue, or the card has been abused or is simply faulty. Could be a card that was overclocked heavily, to death, or used for mining.
Since RX 580 is 185W GPU (5W more than GTX 1080), it's power consumption is in correlation to it's heat output, meaning that it's naturally hot running GPU.
There are 3x things you can do to fix it:
Remove GPU heatsink and replace the thermal paste between GPU die and heatsink, so that more heat get's dissipated by the heatsink and under load temps don't get that high (which in turn can also reduce GPU fan RPM).
Look over your PC airflow and when needed, add more case fans and/or increase the speed of case fans. This helps to cool the insides of the PC and in turn, GPU as well.