You will need a (multiple hard drives striped together) or a dedicated NAS (Network Attached Storage) . A standard external USB hard drive is too slow and unreliable for playback of true uncompressed video.
If you have decided to build a local library of the highest quality video possible, here is the legal, optimal workflow: Download Uncompressed 4k Movies
Before you ask—"uncompressed" doesn't mean raw sensor data. It means . No 15Mbps Netflix bitrate. You will need a (multiple hard drives striped
Crushing blacks, no banding, TrueHD/Atmos that'll shake your room. Worth the bandwidth? Absolutely. here is the legal
, capable of processing high-bitrate HEVC video without stuttering. Conclusion