nvcompress-quick is an update of well-known utility nvcompress (which is a part of NVidia Texture Tools), created as an alternative of CUDA- decision for popular texture formats: BC1(DXT1) and BC3(DXT5). A compressing speed is much higher than in original nvcompress. This speed is being achieved by using a CrystalDXT library as a driver of compression. In addition, textures, made by CrystalDXT, are a little bit more qualitive – it has to do with a colour and especially an alpha channel. There’s also an utility DxtComparer in archive, that you can use to compare *.dds-files. Deflection factor is the same as in Squish/NVTT - square root of the sum of squared differences.
Command-line options are supplemented with 2 settings: "-nocrystal" – don’t use CrystalDXT as a compress driver "-datamode" – don’t use an alpha channel as a colour’s weight
CrystalDXT is my author’s library, made for a work with textures of DXT1/DXT5 formats. nvcompress-quick uses only a part of library, which is responsible for compression. I won’t open its sources, but I can tell the following: the compressing code was based by Squish/NVTT. A speed increase was made by a rigorous code optimization. A texture quality is higher through better precision. By the way, CrystalDXT will be working with the acceptable speed even on those machines, which don’t sustain SSE.