After a while, Plex will need to go on a diet.

The default thumbnail generation in Plex is every two seconds and it doesn’t take much of a library before you’re looking at a 100+ GB Plex installation filled with thumbnails. The thumbnails are nice, but I don’t think that one every two seconds is necessary. I read that some client devices will only show thumbnails every 5 seconds, so that seems like a good tradeoff for size but still have accurate thumbnails. I don’t think that comment was directed at the AppleTV, so I still don’t know what is the optimal interval for an AppleTV.

I changed the setting from 2 seconds to 5 seconds and it really helps save space. It halved my 130+ GB Plex install and I recommend this change to anyone with even a moderately sized library.

The instructions can be found here.

Here were the commands that I used. (Since the Powershell version of curl has different arguments than Linux’s curl, I used the Ubuntu distribution on the Windows Subsystem for Linux and it worked like a charm.)

First, find out the server token with these instructions.

Second, run this command to verify the current setting. It should return default="2" and value="2" on an unaltered install:

curl -s "http://<PlexServerIP>:32400/:/prefs?X-Plex-Token=<plextokenhere>" | grep BIFF

Third, change the value of GenerateBIFFrameInterval to “5” for 5 seconds. (or change this to whatever interval you’d like, but I think 5 is a reasonable choice.)

curl -X PUT "http://<PlexServerIP>:32400/:/prefs?GenerateBIFFrameInterval=5&X-Plex-Token=<plextokenhere>"

Afterwards, run the first command and you should see: value="5".

This will only affect newly generated thumbnails, so delete all the thumbnails in the library and regenerate them.

Plex needs to add this as a user option by default.