the 2.5" size of disks are now mostly direct USB controller disks rather than sata adapters internally.
3.5" disks are still SATA as far as i've seen but the actual sku's of the disks are often the lower grades. like you will get a disk that looks like another good disk but with only 64mb of dram instead of 256 on the one you would buy as a bare internal drive for example so they can end up a bit slower. and warranties are usually void.
Used to be my main source of disks, but these days there are better ways and it is easier to know exactly what you are getting.
Israel making an awful lot of "mistakes" lately...
Are you transcoding?
4mbit per client for 1080 is generally a workable minimum for the average casual watcher if you have H265 compatible clients (and a decent encoder, like a modern intel CPU for example), 6 - 8mbit per client if its H264 only.
Remember that the bitrate to quality curve for live transcoding isn't as good as a slow, non-real-time encode done the brute force way on a CPU. so if you have a few videos that look great at 4mbit, dont assume your own transcodes will look quite that nice, you're using a GPU to get it done as quickly as possible, with acceptable quality, not as slowly and carefully as possible for the best compression.
You're confusing a container format (MKV) with a video codec (AV1)
MKV is just a container like a folder or zip file that contains the video stream (or streams, technically you can have multiple) which could be in H264, H265, AV1 etc etc, along with audio streams, subtitles and many other files that go along, like custom Fonts, Posters, etc etc.
As for the codec itself, AV1 done properly is a very good codec but to be visually lossless it isn't significantly better than a good H265 encode without doing painfully slow CPU encodes, rather than fast efficient GPU encodes. people that are compressing their entire libraries to AV1 are sacrificing a small amount of quality, and some people are more sensitive to its flaws than others. in my case I try to avoid re-encoding in general. AV1 is also less supported on TVs and Media players, so you run into issues with some devices not playing them at all, or having to use CPU decoding.
So I still have my media in mostly untouched original formats, some of my old movie archives and things that aren't critical like daily shows are H265 encoded for a bit of space saving without risking compatibility issues. Most of my important media and movies are not re-encoded at all, if I rip a bluray I store the video stream that was on the disk untouched.
N5095 ? lots of reports of that one not supporting everything it should based on other Jasper Lake chips, CPU getting hit for Decode when it shouldn't for example. Also HDR to SDR cant be accelerated with VPP on that one as far as I know so the CPU gets smashed. I think you can do it with OpenCL though.
Was it an n100? They have a severely limited power budget of 6w compared to the n95 at 25w or so.
I'm running jellyfin ontop of ubuntu desktop while also playing retro games. That all sits in a proxmox vm with other services running alongside it. It's perfectly snappy.
One of my miniPCs is just a little N95 and it can easily transcode 4K HDR to 1080p (HDR or tonemapped SDR) to a couple of clients, and with excellent image quality. You could build a nice little server with a modern i3 and 16gigs of ram and it would smash through 4 or 5 high bitrate 4K HDR transcodes just fine.
Is that one transcoding client local to you? or are you trying to stream over the web? if it's local, put some of the budget to a new player for that screen perhaps?
I've had good luck with WD Blue NVME (SN550)
I've put several of those into machines at work and have had years without an issue. I'm also running a WD Blue SN550 1TB in my server as one of the caches, 25000 hours power on time, >100TB written, temperatures way higher than they should be and still over 93% health remaining according to smart.
Sonarr/Radarr etc make it very easy and safe for media, but apps and games would be more of a serious sit down and talk kind of situation as more can go wrong there.
Soulseek is more like an old school peer to peer network like kazaa, limewire, winmx, ed2k etc.
I haven't seen any clients with a playlist downloader, though that sounds like a cool feature to suggest.
You don't have to seed.
Soulseek has been getting hammered too