AMD's Virtual Super Resolution (VSR) is a new name for a relatively well established form of anti-aliasing - Super-Sampling. In principle the idea is simple: render a scene in a resolution higher than the monitor's native, and then down-sample the scene to the native resolution. In theory this provides the best possible anti-aliasing; you're not relying on complex (and often fallible) edge-detection techniques to discover areas in need of additional sampling or other means to smooth out jaggies, you just simply let your downsampling algorithms do the smoothing for you. Sounds great, right?
Example of 'jaggies' in Far Cry 4 with AA disabled
Unfortunately super-sampling anti-aliasing brings with it one major problem - speed. Rendering a scene at double or four times the resolution is very computationally expensive, and after all necessitated the creation of other anti-aliasing options in the first place. Expecting mainstream GPUs to be capable of this level of performance is simply unrealistic, which is why both NVIDIA and AMD invested resources in developing both open and proprietary anti-aliasing methods which have been incorporated in games engines for years now.
But there has been hope. GPU performance continues to increase apace, and in some cases far surpasses that required to render popular (if not strictly modern) games at far higher resolutions. Knowing this, enthusiasts have continually dabbled with super-sampling unsupported by GPU manufacturers, typically through driver hacks which unlocked the necessary higher resolutions and then downsampled. The spectacular results can be seen with some super-sampled in-game screenshots of games like Skyrim or Crysis 2, but unfortunately game compatibility was often patchy.
Far Cry 4 with computational AA disabled, VSR @ 3200 x 1800
Thankfully GPU manufacturers are starting to get wise to the untapped potential in their high performance GPUs. Earlier this year NVIDIA implemented Dynamic Super-Resol: Virtual Super Resolution.
In theory VSR and similar techniques offer a number of advantages over situations where their use is not possible. Primarily image quality will be improved, although this will generally be quite subjective. Another benefit is that, by using higher rendering resolutions, you can more accurately assess whether your particular system is capable of supporting a high resolution panel without spending any money up front. Furthermore the technique is broadly independent of the game engine, i.e. rather than needing to incorporate the technique into their game engine it should be supported be default (so long as the title supports the VSR resolution at all).
So, all in all Virtual Super Resolution looks like an excellent inclusion for Catalyst Omega. We'll see how it performs a little later.