The ASUS GTX 780 STRIX 6 GB introduces a new feature to the GPU world: fanless operation in idle. Technically, we saw such a feature many years ago, but it has now been used on a modern graphics card for the first time. Rest assured, the card does not overheat or become unstable. Heat output of modern graphics cards is so low that pretty much any card will be fine with the fan(s) disabled when it's cool enough. As a manufacturer, you just need to have the balls to do so. The GTX 780 STRIX is ASUS's GTX 780 6GB implementation. The card comes overclocked to a base clock of 889 MHz out of the box, but runs around 1020 MHz most of the time because of NVIDIA Boost. Unfortunately, memory is not overclocked, which would have yielded a nice additional performance increase. Overall, this makes the card roughly 12% faster than the reference design GTX 780 with 3 GB. But hold your horses as this increase is only achieved by the overclock out of the box. The extra memory really doesn't do anything in all but one game, Watch_Dogs, and that at only one resolution, 4K. All other games at all other resolutions, including 4K, don't show a noticeable performance improvement. There is also no way for a current GPU to drive a 4K monitor at playable framerates by itself, no matter how much memory it has. There is simply not enough shading power. The additional memory doesn't even make enough of a difference in SLI to make up for the cost. The ASUS GTX 780 STRIX is roughly on the same performance level as AMD's R9 290X, 3 % faster than the Titan, but 9% slower than the GTX 780 Ti.
It looks as though ASUS designed the fan-less feature well. The fans will not spin up until GPU temperature exceeds 65°C for several seconds, and nor will they simply start and stop at around 65°C, which could result in a very annoying loop of continuous starts and stops. I found idle temperatures to be acceptable. They are about 15°C higher than comparable cards, but are still low enough to not pose a threat to the card's circuitry. However, I would have wished for better noise levels while gaming. It seems as though ASUS tuned their fan profile to keep temperatures below 75°C at full load, which is certainly nice, but creating a no-noise card in idle only to have a noisier fan than competing products with mid-high loads makes little sense to me. MSI's GTX 780 GAMING 3 GB is extremely quiet in both idle and load. Actually, I wonder whether it's really worth the engineering effort to completely turn the fan off versus running it at a very slow speed, which is just as inaudible. Such a passive operation certainly makes sense from a marketing perspective, to innovate in the currently stagnant GPU market.
Retailing at round $590, the ASUS GTX 780 STRIX 6 GB is not cheap. It costs $100 more than the cheapest GTX 780 with 3 GB, and certainly doesn't provide a performance improvement worth those $100. NVIDIA's GTX 780 Ti retails for $660, which is another $70 increase, but it performs better in all scenarios except for Watch_Dogs at 4K, where we saw the extra memory provide a benefit. Unless you have a specific need for 6 GB, you will be much better off buying a GTX 780 3 GB or spending a bit of extra money on a GTX 780 Ti. The new ASUS STRIX feature is certainly nice and good, but wouldn't be worth the extra cost to me, and I am really concerned with noise levels when it comes to my work PC. Unlike the MSI GTX 780 6 GB, which barely missed its Recommended Award, I'm giving it to ASUS because their card brings with it a bit of innovation, which shouldn't cloud your judgment when it comes time to decide whether you really need a 6 GB card.