I'm running Jellyfin on a mini desktop PC. It's probably 7+ years old now. I upgraded to a 14T external hard drive because I'm on an archival kick. Now, while I do re-encode nearly everything just to keep the sizing down, on a separate computer, I never have trouble browsing in the Jellyfin app. It's very snappy and nothing has buffered for years.
I've never had trouble browsing, but my re-encoding may be why I don't have any issues.
