AMD Radeon R9 295X2 Review: Hawaii x 2
The AMD Radeon R9 295X2 is a complete departure from previous-gen Radeons. Gone are the plastic fan shrouds, in favor of all metal construction. And cooling each GPU is a closed-loop, liquid cooling system with dual heat plates and a 120mm radiator assembly. There is still a fan on the card itself, but it is used to cool the VRM and other surface mounted components.
The Radeon R9 295X2 is a full 12” long, and as we mentioned earlier, packs a pair of full Hawaii GPUs. The two GPUs combined equate to roughly 12.4B transistors and offer compute performance of up to 11.5 TFLOPs. There are a total of 5632 stream processors (2816 per GPU), with 8GB of GDDR5 memory (4GB per GPU) running at 5Gbps, linked to the GPU on dual 512-bit memory interfaces. The GPUs can clock up to 1018MHz and feature Hawaii’s full complement of texture units and ROPs. Peak textured fill-rate is 358.3 GT/s and pixel fill-rate tops out at 130.3 GP/s. For all intents and purposes, the R9 295X2 is a full Radeon R9 290X CrossFire configuration on a single card.
With the kind of complexity and horsepower at its core, it should come as no surprise that the Radeon R9 295X2 has some special cooling and power-related considerations. As we’ve mentioned, the card is liquid cooled and has a 120mm radiator assembly. That radiator needs to be mounted properly in a case—preferably using a 120mm fan mount at the rear or top of the case. The card also has a TDP of 500 watts and requires dual 8-pin PCI Express power connectors. Just having the necessary connectors isn’t enough, though, as the power supply feeding the card also needs to be able to handle a minimum of 28A on each of the 12V rails powering the card (or a single, more powerful 12V rail). We had a 1200 watt PSU in the lab with six 12C rails capable of supplying 17A and it could not handle the Radeon R9 295X2.
The cooling solution on the Radeon R9 295X2 was developed with Asetek. If you’re unfamiliar with Asetek, they are one of the pioneers in self-contained, high-performance liquid cooling solutions. The cooling hardware on the R9 295X2 consists of a pair of copper cold-plates, with micro-channel fins and integrated pumps, which sit directly atop each GPU. There is a long heat plate/mount that covers the entire front of the PCB, save for a small portion in the center that accommodates a separate cooper heatsink mounted to the card’s VRM. There is another metal plate covering the backside of the card to add rigidity and the front is covered up with an all-metal shroud. The cooling fan in the center of the shroud lights up red, as does the large Radeon logo cut into the top of the card. All told, it’s a pretty cool design.
Outputs on the Radeon R9 295X2 consist of a single, dual-link DVI output and four mini-DisplayPort outputs. All of the outputs on the card can be utilized at once should you want to setup a multi-monitor Eyefinity configuration and the DP outputs are v1.2, and support MST mode on 4K displays.
Of course, the Radeon R9 295X2 supports AMD’s other graphics technologies like TrueAudio, Mantle, CrossFire, and the like. Just in case you’re wondering, it is possible to have a pair of these things in a single system, for a quad-CrossFire configuration.