Nvidia is pouring in a lot of resources into the GTX 680; the end result isn’t just a card that runs cooler and quieter than the previous generation (although that is solely due to the shrinking die size), but also a card with some cool new features.
A good look into all of these can be seen from the small video below, as Nvidia nicely sums up and visually displays how these new features on the GTX 680 work and look like in real life.
The GPU Boost feature can be thought of as Intel’s and AMD’s Turbo Boost technology. Given that the GPU is not under full load, there’s enough headroom for a minor overclock to boost performance in-game. Obviously all of this is done automatically, and Core clock speeds can go from 1006MHz to 1059MHz. In the future, as Nvidia teams up with more game developers, we will be seeing this technology being used more efficiently, to a point where people may not even need to overclock their GPU anymore.
Sadly this is where actual overclocking suffers, as increasing the Core clock speed up to 1200MHz actually resulted in either the exact same performance as stock, or drop in certain cases by a frame or two. The GTX 680 just continuously offsets clock speeds against the voltage, or TDP to be more precise. I’m sure in the near future certain manufacturers, namely MSI, ASUS and perhaps EVGA will release updated overclocking software that allows further tweaking; but for now, everyone is stuck with Nvidia’s nanny for overclocking.
Another cool new feature is Adaptive VSync, whereby the Kepler architecture dynamically turns VSync on and off whenever frame rates dip below 60fps to avoid the stuttering effect many people notice in games as the GPU cannot maintain 60fps lock due to excessive GPU usage. VSync, when left on, adds a lot of stress on the GPU, and if frame rates cannot be maintained, frame rates take a nose dive, resulting in the stuttering; Adaptive VSync will simply turn off VSync in order to avoid this issue altogether. Once frame rates go up again, VSync is turned on so that screen tearing doesn’t occur as frame rates swiftly move from over 60 to 80 or more, down to 60, etc.
The last new feature worth mentioning is NVidia’s new antialiasing technique, called TXAA. TXAA is a mixture of regular antialiasing and a special ‘CG film style AA resolve’ which results in extremely smooth edges without impacting the GPU by as large a margin as regular MSAA. In fact, Nvidia claims that 1xTSAA provides better quality than 8xMSAA, while only consuming the resources equivalent to 2xMSAA. Conversely 2xTSAA uses the power consumption equivalent of 4xMSAA. Currently there are 9 games in development that will use NVidia’s TXAA which will be utilized by the GTX 680, to be released later this year. Specific games include Borderlands 2 and Mech Warrior Online, while Epic’s Unreal Engine 4 as well as Crytek’s next engine will be supporting TXAA.