This is particularly common among Plex users with underpowered servers, as transcoding x265 to x264 for incompatible clients can be extremely CPU-intensive. Hardware acceleration (Intel Quick Sync, NVIDIA NVENC, or AMD VCE) can mitigate this, but not all setups have access to these features.
For years, Elias had been a "Remux" purist—nothing but the highest bitrate, uncompressed 4K files. But then came the Great Storage Crunch of '26. His 100-terabyte NAS was gasping for air, the red warning lights blinking like distressed eyes. He had two choices: spend a fortune on new drives or embrace the efficiency of
:
In Sonarr’s Custom Formats section:
As video compression continues to evolve, AV1 has emerged as the successor to HEVC, offering even better compression efficiency (approximately 30% better than x265) without the licensing headaches associated with HEVC. sonarr prefer x265