What do you recommend to use?

My server has an Intel(R) Xeon(R) CPU E5-2697 v3 @ 2.60GHz CPU.
I want to use thumbnails, but in your documentation i see:

Flussonic Media Server does a rather CPU-intensive job: it takes the first keyframe of each segment, decodes it to raw video, and encodes back to a JPEG image. This seems rather simple, but when you have, say, 300 streams, this process can take a lot of CPU time.

What do you advise?

We are recommend to use video-thumbnails it’s minimize system overhead to creating thumbnails.
A video thumbnail is a piece of H.264 video contained in a single keyframe.