A long-time favorite tool among transcoders is the Tsunami MPEG Encoder, or TMPGEnc, now owned by Pegasys in Japan. Within the video community, TMPGEnc is considered one of the highest quality transcoders available, although not necessarily one of the fastest. We used TMPGEnc 4.0 Xpress with a 15-second, 1440x1080 clip supplied by Pegasys.
Unlike some other transcoders, TMPGEnc only uses CUDA for effects acceleration. The encoding process itself is currently not GPU-accelerated. You’re only going to see benefits from CUDA here when the transcode process involves effects/filters such as noise reduction, sharpening, and so on. This is why you need to read the fine print before investing in acceleration technologies and the apps that use them. Make sure that not only the application you’ve picked but also the functions that you need from that application will deliver what you expect.