dagoelius :
Hi 9Meez hope this helps,
Ive had my Gigabyte R9 390x for a while now and when surfing the net, youtubing etc its idling between 58-60 degrees and runs around 70-75C when gaming, so your results are a little high but not much.
When i first installed the 390x graphics card, my rig was plugged into a simple surge protector ups unit and soon as i started a game the warning bells would sound and the ups would trip the surge circuit! (have to run my rig straight from the main power socket now till i can update to more robust UPS) It pulls some serious power when running full flight.
Do you have an audio card occupying the slot above the R9 390X? I did notice (via my case monitoring sensors) it can add to the overall heat generated in that area.
When I removed the audio card and ran audio straight from the motherboard the heat dissipation from the gpu was much better around 5 degrees less.
What case do you have? I've got a monstrous Cosmos which has heaps of internal space for moving air around plus the whole side panel has a massive fan keeping everything inside well aerated.
I plan to strip the fan and put a liquid cooling block on the 390X as I've read you can get a nice reduction in heat output in doing so.
Hi Dagoelius,
Thank you so much for sharing your response. Actually I have finally come to know how to keep this GPU running in cooler temperatures. Yes my temperatures are also in 40 to 50 degrees in idle states or while watching videos it keeps hovering between 50 to 60 degrees and sometimes remain below 50 as well. That's alright I believe.
Ok now lets share some interesting experience here while gaming, In first place when I installed this card into my rig, I tested the card on few latest titles like COD Advanced Warfare on Full High Settings ( MAX settings ), the temperature was falling between 85 to 90s. Now my temperature for this game has decreased almost 10 degrees , just because i have disabled the "super sampling" option of the game which was previously on 8X or 16X and that was squeezing the juice from the GPU. And believe you me there was no major image quality difference so there is no reason for me to play the game , while frying your GPU just for this single option

Besides this game is not optimized yet and keep crashing as well. Also when I run this game on 4K resolution temperature goes till 85 degrees which is fine as well.
Similarly I tested the card on, Sleeping Dogs, same case was happening, in first place on Full High settings / Ultra settings temperature hit to 90 degrees just because of Max Anti aliasing. Then I set the Anti Aliasing to 4x and the temperature never hit above than 77 degrees.
So what i believe the games which are not optimized well enough you have to only keep your anti aliasing at mid level and you temperatures will fall down almost 10 degrees. Where as there are games which are optimized enough like MGSV phantom Pain, on ultra / max settings 1080P my temperature never hit above than 77 degrees on an average in this game. Also Batman Arkham Knight on ultra settings 1080P temp was between 75 to 80s. If i run both of these titles in 4k temp increases almost 5 to 6 degrees more which is fine.
So lets cut to the chase, there are titles where we have to keep adjusting the only thing which is Anti Aliasing and there are titles which are so optimized enough that you don't have to worry about this option and you are good to go, Thanks please keep sharing your feed backs and results if it helps.