Hello guys i wonder what fan speed is best for our GPU on mining?
100% or Auto ?
100% will kill your fans.
Not sure about ATI cards, but Nvidia cards allow you to set a temperature threshold that lets the fans operate at whatever speed is required while limiting the amount of power the cards draw. Not quite auto, it's a bit more complex, but super effective.
Fans are consumables. Replacement fans time by time is much easier the replacement whole GPU. So 100% fan speed is not so scary. But using MSI AB for example one can setup fan speed curve from 40% fan speed at 50C to 100% at 70C temp