How big is the difference between a dual fan and a three fan gpu? Will I see a significant temperature drop on a Powercolor R9 390 (3 fan) vs an MSI twin Frostr R9 390 (2 fan)?
One more question. Is it normal for GPU fan to stop spinning at idle?
Usually the temperatures are very similar. The two fan GPU's are usually taller allowing for bigger fans while the 3 fan GPU's are shorter but longer to accommodate the 3 fans. So the two bigger fans perform similarly to the 3 smaller fans.
About the fans not spinning at idle yes this is normal. New GPU's have it built in the BIOS to have the fans stop spinning when the GPU reaches a certain temperature.
Usually the temperatures are very similar. The two fan GPU's are usually taller allowing for bigger fans while the 3 fan GPU's are shorter but longer to accommodate the 3 fans. So the two bigger fans perform similarly to the 3 smaller fans.
About the fans not spinning at idle yes this is normal. New GPU's have it built in the BIOS to have the fans stop spinning when the GPU reaches a certain temperature.