At first glace, the recent addition of “hardware acceleration” when exporting to H.264 and H.265 in Media Encoder and Premiere Pro provides a huge boost in performance for many users. Unfortunately, it is not a perfect technology and result in lower quality video than using the standard “Software only” mode.
Media Encoder CC 2018 Transcoding: NVIDIA GeForce vs AMD Radeon Vega
Depending on how you use Media Encoder, the GPU may or may not have a large impact on performance. If you use it primarily as a transcoding tool, it should be mostly CPU-bound – so is there any reason to use NVIDIA GeForce over AMD Radeon or vice versa?