Deep learning super sampling

Deep learning super sampling (DLSS) is an image upscaling technology developed by Nvidia and exclusive to Nvidia graphics cards for real-time use in select video games, using deep learning to upscale lower-resolution images to a higher-resolution for display on higher-resolution computer monitors. Nvidia claims this technology upscales images with quality similar to that of rendering the image natively in the higher-resolution but with less computation done by the video card allowing for higher graphical settings and frame rates for a given resolution. Nvidia claims “DLSS 2.0 offers image quality comparable to native resolution.”
As of December 2020, this technology is available exclusively on GeForce RTX 20 and GeForce RTX 30 series GPUs.
History.
Nvidia advertised DLSS as a key feature of the GeForce RTX 20 series GPUs when they launched in September 2018. At that time, the results were limited to a few video games (namely Battlefield V and Metro Exodus) because the algorithm had to be trained specifically on each game on which it was applied and the results were usually not as good as simple resolution upscaling.
In 2019, the videogame "Control" shipped with ray tracing and an improved version of DLSS, which didn't use the Tensor Cores.
In April 2020, Nvidia advertised and shipped with driver version 445.75 an improved version of DLSS named DLSS 2.0, which was available for a few existing games including "Control" and "", and would be available later for upcoming games. This time Nvidia said that it used the Tensor Cores again, and that the AI did not need to be trained specifically on each game. 
A side effect of DLSS 2.0 is that it seems not to work very well with anti-aliasing techniques such as MSAA or TSAA, the performance being very negatively impacted if these techniques are enabled on top of DLSS. 
As of April 2020, DLSS 2.0 must still be included on a per-game basis by the game developers.
Algorithm.
DLSS 1.0.
Nvidia explained that DLSS 1.0 worked for each target game image by generating a "perfect frame" using traditional supersampling, then trained the neural network on these resulting images. On a second step, the model was trained to recognize aliased inputs on the initial result.
DLSS 2.0.
DLSS 2.0 works as follows:
Architecture.
DLSS is only available on GeForce RTX 20 and GeForce RTX 30 series GPUs, in dedicated AI accelerators called Tensor Cores.
Tensor Cores are available since the Nvidia Volta GPU microarchitecture, which was first used on the Tesla V100 line of products. Their specificity is that each Tensor Core operates on 16 bits floating point 4 x 4 matrices, and seem to be designed to be used at the CUDA C++ level, even at the compiler level.
The Tensor Cores use CUDA Warp-Level Primitives on 32 parallel threads to take advantage of their parallel architecture. A Warp is a set of 32 threads which are configured to execute the same instruction.