The temperatures you see in the graph below show that partner boards run quite a bit cooler than AMD's reference design. In fact, Sapphire's offering even matches one of our favorite GeForce GTX 780 cards from Gigabyte. As it turns out, the Hawaii-based flagship is perfectly capable of running well in a closed case, so long as it's cooled properly.
Let's get into the results themselves. Each of these boards is tested for 20 minutes using Metro: Last Light at its highest settings.
Asus' R9 290X DirectCU II OC fares the worst, even though its 84-85 °C temperature is still bearable. The Tri-X OC Radeon R9 290X shows that Hawaii can run quite a bit cooler, though, topping out at 72 °C. Sapphire's result is particularly impressive. In our closed case test, the Tri-X registers 1-2 °C lower than in the open-air chassis. The Asus card's temperature, on the other hand, increases nine degrees from our measurement using the exposed bench system. And what's up with Gigabyte's R9 290X Windforce OC? With a reading of 83-84 °C in the closed case, that's just under Asus' board. But it's still one degree lower than our open case result. Apparently, Quiet Mode was taken too literally; a slightly faster fan would have probably been acceptable.
It turns out that the Asus and Gigabyte cards suffer the same problem. Instead of a solid base drawing heat away from the GPU, both employ evidently unfavorable direct-contact heat pipes. The tapered surfaces don't make sufficient contact with the GPU, especially the two outer pipes that essentially do nothing. A vapor chamber or massive sink would have been much more useful.
Then again, that's what you get when you recycle the same cooling found on Nvidia's GeForce GTX 780 for reasons of economics. Cheers, accountants!
Microcool Banchetto 101
|Asus R9 290X DirectCU II OC||76 °C||84-85 °C|
|Sapphire R9 290X Tri-X OC||73 °C||70-72 °C|
|Gigabyte R9 290X Windforce OC||84 °C||83 °C|
|Gigabyte GTX 780 Windforce OC||67 °C||68-69 °C|
What do these thermal measurements tell us? A well-designed case won't necessarily impose higher temperatures on your graphics card, even if its GPU is notoriously hot and it employs axial fans that recirculates heat. The key appears to be a thermal solution optimized for the application, and not something tacked on as an afterthought.
Our acoustic measurements come from recordings using a calibrated studio microphone. It's oriented diagonally from top-left to bottom-right, pointing towards the upper-left case edge. That should roughly correspond to a gamer's seated position, 50 cm away. We keep the previously-mentioned Metro: Last Light gaming loop running.
Microcool Banchetto 101
|Asus R9 290X DirectCU II OC||42.3 dB(A)||47.3 dB(A)|
|Sapphire R9 290X Tri-X OC||40.9 dB(A)||43.8 dB(A)|
|Gigabyte R9 290X Windforce OC||41.9 dB(A)||45.8 dB(A)|
|Gigabyte GTX 780 Windforce OC||39.5 dB(A)||43.6 dB(A)|
Even though each board's behavior is fairly consistent in and out of our test chassis (except for Asus' model), this comes at the cost of slightly higher background noise. Components mounted inside the case, with a passive graphics card installed, generate background noise of 36.7 dB(A), so our measurements are the sum of those two sound sources. With this in mind, acoustics are certainly better than AMD's reference effort, but could still be quieter. This applies to Gigabyte's GeForce board as well, to a lesser degree.