I will be running Truenas scale with ZFS, so will be installing 32GB of memory.
I realize a full size PCI slot would be better, but not really necessary for my application. Both have 6 SATA and two M.2s. I could put a 6 SATA/M.2 adapter in when I need more HDs. I'm really just comparing these two, and I don't really see any disadvantages to the N100 board.
It is listed at 32GB, but I've seen folks online who have installed more and tested it. Same 16GB limit listed with the N5105 that I currently have. I have 32GB on that and tested it.
Sorry I can't help with your question, but I wanted to ask what features you feel Jellyfin is missing that is keeping you on Plex? I've made the switch, and actually like Jellyfin better.
Just went through this myself and settled on DIY build. Someone recommended this video, and I followed it very closely. The built was so easy and less expensive than off the shelf. I installed TrueNAS on it and couldn't be happier.
I'm very happy with my current N5105 board that I linked, even though it doesn't have any PCI slots. With 6 SATA and two M.2s I should be ok. If necessary I can add a 6 SATA M.2 adapter to get up to 12, which is definitely more than I need. If/when I get 10gbe I would have to upgrade either of these to get those speeds. Although a M.2 PCI riser with a 10gbe card would get me ~7gb so that is also an option.
Any thoughts on these two boards? I don't see any real disadvantages to the N100 board when compared to the N5105.