The most important question: 3 transcodes of what?
If you only have 1080p max resolution and no video using the HEVC codec, this cpu can handle it easily. https://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i3-9100F+%40+3.60GHz&id=3461
It has a relatively good ‘single thread rating’, so it is well suited for Plex, IMHO.
It might be able to handle HEVC video if you enable hardware transcoding.
Don’t skimp on a proper cpu cooler
(and don’t make the case so small that you cannot fit a proper cooler into it).
I recommend to use a bigger cooler intended for overclockers. These are highly efficient and use big fans, which, when slowed down are still virtually silent.
This ensures that even under full load your cpu won’t go into “thermal throttling” and starts to sound like a jet engine
One comment. The F processors do not have a GPU, so you won’t be able to take advantage of hardware accelerated transcoding.
Using the GPU for video transcoding greatly reduces the load on the CPU. It will also give you some headroom for future growth (more transcoded streams, HEVC video, etc).
The i3-9100 is about $20 USD more than the i3-9100F on Amazon (9100, 9100F).
Something to consider before finalizing your purchases.
Here in Brazil I could not find i3-9100
So i am thinking to get i5-8400 with MB gigabyte B360 M.
Is it a good choice? .
I Just want (maximun) 3-4 1080p to 720p H.264 concurrent streams. No 4K or H.265.
