AMD's Radeon R9 295X2 is an impressive piece of engineering. They managed the seemingly impossible: cram two fully unlocked, fully clocked Hawaii GPUs onto a single graphics card. AMD's ace up their sleeve is the watercooling solution from Asetek, which, despite being relatively compact with just a 1x 120 mm radiator, can handle the heat output of both GPUs quite well.
In terms of performance we see truly impressive 4K resolution numbers from the R9 295X2, which are essentially twice those of a single R9 290X card. With these results, R9 295X2 is the fastest single card solution available today, and a great choice for this resolution, as well as 5760x1080 EyeFinity. Thanks to the low temperatures, provided by watercooling, the card does not throttle during normal games, which means you have its full potential available at all times. Unlike a single GPU card, being based on two graphics processors, the R9 295X2 needs good drivers to show proper performance improvements in games. Thanks to updated AMD driver support we see better CrossFire scaling across our test suite than ever before, the only game which does not scale properly is Diablo 3: Reaper of Souls. This marks a significant improvement over the last time when we looked at CrossFire (HD 7990), where six out of 18 games did not scale as expected. It still shows that you may be left with single GPU (R9 290X) performance, when a new title comes out for which CrossFire support is not available immediately. Also at lower resolutions, 2560x1600 and below, scaling is slim in general, and I would not recommend the R9 295X2 or any other multi-GPU solution for these setups. A powerful single GPU card like NVIDIA's GeForce GTX 780 Ti, or Titan will definitely do better at 2560x1600 and be more cost efficient at the same time.
In order to keep their card at sane temperature levels, AMD has opted for a watercooling solution by Asetek, who are one of the leaders in this field of technology. The Asetek watercooling works flawless, comes prefilled, is self-contained and maintenance free. You just install the card, find a spot for the radiator and power it up. The first minutes you'll hear some noise due to air bubbles circulating in the loop, but this sound goes away quickly and the two pumps (one for each GPU), are almost inaudible. Nevertheless, watercooling always introduces more complexity into a system, which could be troublesome especially in smaller cases. At full load, the watercooling radiator gets quite warm, you won't burn yourself, but it will feel hot to the touch. The 500W+ heat output will definitely heat up your room, and there is no way around that, the heat just has to go somewhere. While many might say that the 120 mm radiator is too small, it does a fine job and keeps the card at good temperatures, but does so with a bit much noise. Temperatures under load are around 60°C, so in my opinion, AMD could have run the fans slower, to reduce fan noise.
A second fan is installed on the graphics card itself and its job is to cool voltage regulation circuitry and memory chips. This fan is working extra hard and tends to be noisy. I'm also wondering if this part of the thermal solution is designed properly. Under full load, our new thermal imaging camera reveals that the back side of the card reaches over 100°C, showing heat travelling through the card from the VRM circuitry on the front, which means these components are even hotter. Taking a closer look, it seems that the heatsink fins under that fan are oriented the wrong way, they direct air to the sides, to the walls of the waterblocks, instead of up and out of the card. Maybe AMD should have used a single, full-cover block that cools all components, to avoid these troubles.
Another surprise is that the card still has some coil noise (listen for the chirping noises in our thermal imaging video), while less pronounced than on the HD 7990, it is still there. After all the HD 7990 drama, I expected AMD to make 100% sure that it wouldn't happen again. Depending on the situation (FPS, game, load) the noise changes in volume and frequency, so it's very noticeable and distracting at times. In general I find the acoustic footprint of the card higher than what would be necessary, especially in idle. Under load the card runs at noise levels comparable to other high-end cards (that are slower of course), but I feel that AMD could have optimized things a bit better. With current drivers, the card has absolutely no fan control or fan speed monitoring, which means you can't just adjust things on your own.
AMD is asking $1500 for the R9 295X2 which is simply too much. Right now, the R9 290X retails around $570, so I don't see a reason why AMD needs to charge $1500, other than "because we can", "because NVIDIA charges more". In my opinion a more reasonable price for the card would be sub-$1000, probably around $900. It's not the second coming of Christ, still has some technical difficulties, but its performance at 4K is simply impressive. Given NVIDIA's announced $3000 pricing for the Titan-Z, which I doubt will be much, if any, faster than the R9 295X2, the R9 295X2 suddenly looks affordable. But if I were to build a 4K gaming system I'd just use good old CrossFire and SLI to build up my rig using R9 290X or GTX 780 Ti at much better pricing, and end up with the 4K monitor for almost free. Personally I'm not so convinced that 4K is a must anyway, in most games I see very little difference between 2560x1600 w/ AA and 4K w/o AA, so little that I wonder if the performance hit is really worth it.