: Improved GPU acceleration for faster rendering of effects. Smooth Playback
Prior to 14.2.1, users complained incessantly about persistent notification icons that wouldn't clear, or the "Adobe GC Client" executable that seemed to hang in the background. The 14.2.1 build addressed these background processes, resulting in a lighter footprint on system resources—a crucial factor for rendering heavy compositions. adobe after effects cc 2017 1421 extra quality
As for the "1421" part, I couldn't find any specific information related to this number. If you could provide more context, I'll be happy to help you understand its significance. : Improved GPU acceleration for faster rendering of effects