Nvidia launched Dynamic Super Resolution (DSR) with the Maxwell GPU architecture in September, but in essence it’s a driver-level implementation of a process which is already well understood. The technique is now available to both Maxwell and Kepler-based GPUs, i.e. cards ranging from the GTX 600- through to the latest GTX 900-series.
Super Sampling Anti-Aliasing (SSAA) isn’t a new concept, but its adoption in games or graphics hardware over the years has been patchy due how processor-intensive the process is. SSAA relies on sampling the scene at a resolution much higher than your native screen resolution and then blending pixels together to output a 'normal' resolution frame, reducing ‘jaggies’. It’s often colloquially referred to as the ‘king of AA techniques’, but has given way to MSAA, MLAA and Nvidia’s own FXAA, each of which are faster and less computationally expensive even if the quality isn’t as good.
Progress in graphics technology and horsepower has meant that a game which would bring a GPU to its knees five years ago can be comfortably played on mid-range hardware these days, whilst top-tier hardware push frame rates well into the hundreds. The now classic example is League Of Legends, which can famously be played at 1080p @ 60fps V-Sync without the need of a single spin of a mid-range GTX 960’s fan. That’s a lot of horsepower going to waste when it could, if the game supported it, be used to improve image quality significantly.
Relatively recently enthusiasts have used a homebrew technique to increase the resolution which a game engine renders at, and then apply post-processing techniques to reduce the output resolution down to the monitor’s native. Known as downsampling, it's essentially a form of SSAA. Unfortunately it’s very hit-and-miss, often reliant on 3rd-party applications and prone to throwing up OS-level errors; and of course it’s very computationally expensive. However the rewards – beautiful images from older game engines – make the effort worth it.
Today GPUs such as the GTX 980 are being produced which are capable of and designed for 4K resolutions in even modern titles. However most gamers still use 1080p monitors on a day-to-day basis, making a $500+ GPU obscene overkill for all but the most taxing of titles. Because of this Nvidia have started to support downsampling at the driver level through the method they’re calling Dynamic Super-Resolution (DSR).
Composite scene, DSR sample on right
Using DSR - which can be enabled automatically through GeForce Experience or the driver application- the game is rendered at a higher resolution and then downscaled to the monitor native resolution. DSR, like AMD’s Virtual Super Resolution, is implemented at the driver level and so is generally supported by all game titles which has rendering at user-selected resolutions as an option.
Whilst the potential image quality benefits are significant it’s also worth noting that DSR is an excellent measure of assessing whether your setup is capable of supporting a higher resolution monitor in gaming. Nvidia estimate that the performance impact of the downsampling process is apparently only 1-2% (i.e less than a frame per second), so the framerates you get running DSR at 4K on your 1080p monitor will be close to those you get for 4K natively. We’re not sure if Nvidia intended this, but we’ll certainly take it.
