The tests were performed in a controlled room with temperatures maintained at a constant 25°C – a comfortable summer environment for the majority of people reading this. Idle temperatures were measured after sitting at the desktop for 15 minutes. Gaming measurements were acquired by repeating the GTA V benchmark for 15 minutes and taking the stabilised reading. All fan settings were left on automatic.
The R9 295X2 was tested using Metro: Last Light, rather than GTA V, due to its operating bug with the latter.
AMD's cards and their AIO liquid cooling units take convincing performance leads in the thermal performance chart. Actual operating temperatures of those cards will vary heavily based on radiator positioning, however they are always likely to outperform the air-cooled solutions even if the cards themselves consume more power at any point of usage. That's the benefit of using liquid to dump large packets of heat onto a dense radiator.
The 0dB mode of EVGA's card sees idle temperatures register 47°C. This is comfortable for a card that is silently sat at the Windows desktop or just browsing the web. Load temperatures hit 77°C, which leaves a safe margin between the 83°C thermal threshold of Nvidia's GTX 980 Ti GPU.
This is pretty much exactly how a graphics card backplate should be implemented. The intelligent design and contact points ensure that heat is effectively spread away from the GPU core area to all ends of the metal backplate. This increases the effective cooling surface area and allows more heat to be removed from the card.
A temperature difference of less than 10°C between the hottest and coolest parts of the backplate speaks volumes for the superb effectiveness of EVGA's design. And a maximum hot-spot temperature of 66°C (behind the power delivery MOSFETs) is no cause for concern, even if cables or cooler tubing are in physical contact with the area.