https://helpx.adobe.com/premiere-pro/using/whats-new/2021.ug.html"New hardware decoding using AMD and NVIDIA GPUs on Windows offers faster playback and more responsive Timeline performance for the widely used H.264 and HEVC formats in Premiere Pro and After Effects. For information on preference settings for this feature, see Set Media preferences."
https://www.pugetsystems.com/labs/articles/Premiere-Pro-GPU-Decoding-for-H-264-HEVC-media---is-it-faster-1908/