Currently using Sony MovieStudio 13 Platinum (SMS13P) to cut video files together but have been looking for increased performance on final (mp4/h264) rendering and found this isn’t so simple for the initiated. To put some context: video rendering is processor intensive but over recent years some rendering (to file) tasks can be taken up by the graphics card GPU as well being done by the CPU. Whilst this may seem counterinteritive at first, the CPU has a limited set of (typically of consumer systems, 4 to 8) cores but a GPU may have cores numbering in 1000s (a high end consumer Nvidia GTX Titan has over 3000 cores) and the GPU can be more efficient on simple repetitive tasks.
