Nvidia unveiled the GeForce GTX 690 earlier this week. It’s a bi-GPU card from the Kepler generation derived from the GeForce GTX 680. Given the contained energy consumption of the GK104 GPUs it runs on, its spec hasn't been revised downwards by as much as bi-GPU cards often are what with thermal envelope limitations. The GeForce GTX 690 GPUs will be clocked at 915 MHz, as against 1006 MHz for the GeForce GTX 680. There will of course be a turbo mode, with a GPU Boost clock announced at 1019 MHz, against 1058 MHz for the GeForce GTX 680. Each GPU has 2 GB of GDDR5 memory clocked at 1502 MHz.
Remember, the GPU Boost clock isn’t really a spec and is only a communications ploy. The real turbo clock is equal to or higher than this figure but variable, depending on the environment and quality of the GPU (current leakage) and the individual sample: Nvidia sells same reference GPUs validated at different clocks (between 1071 and 1110 MHz for the GTX 680) so that it can offer a certain number of “top performance” GPUs while maintaining a sufficiently high production volume. This is something that went unnoticed at the launch of the GTX 680 and we'll be coming back to it as soon as we can. This explains why Nvidia is uneasy when speaking about GPU Boost specs.
As with the GeForce GTX 680, Nvidia is categorically refusing to give any information on the real specs and the variation we can expect. This makes it difficult to ascertain exactly how the GeForce GTX 690 will perform in comparison to two GTX 680s in SLI, but we estimate that the SLI system will have around a 10% advantage.
Nvidia has abandoned its in-house switch so as to retain the GK104’s PCI Express 3.0 compatibility and moved to using a more recent PLX part. Although its TDP is around 300W and the GPU Boost is limited to 263W (maximum value for clock increases, though it isn’t reduced under 300W), the GeForce GTX 690 uses two 8-pin PCI Express connectors (375W), leaving a decent overclocking margin. The drivers allow you to increase the GPU Boost target by 35% to a max of 355W.
Nvidia has been talking up the design of the card, the materials of which have been reworked top to bottom to give it irreproachable manufacturing quality with aluminium and composites replacing the usual plastic. The cooling system is however very similar to the one used on the GeForce GTX 590 with two cooling blocks equipped with a vapour chamber and cooled by a central axial fan. Given the better contained energy consumption, noise levels should however be lower here. The connectivity is also the same: 3 DVI Dual-Link outs and a mini-DP out.
Unusually, Nvidia decided not to give information to the trade press in advance of launch and only supplied test cards once the announcement came into effect (earlier in the week). This approach has meant that Nvidia has been able to control what information was coming out on this card and prevent AMD from getting any advance knowledge to help it in preparation of its own bi-GPU card. A standard launch would have meant that AMD could check out the positioning of the card and potentially supply it’s own test card just before Nvidia’s announcement. On the other hand, proceeding like this has also prevented us from giving you the usual full review and encourages the various media outlets to be less circumspect and, once they have the card in hand, to hurry out the first benchmarks as fast as they can.
We therefore advise you not to take these early benchmarks too seriously and wait for full tests before you get into hot water with your bank and invest in such a model. Nvidia has announced the first available cards for May 3rd at something in the order of $999! We’ll try and publish a review of the GeForce GTX 690 as soon as possible.