NAS Buying Beginner?

[lucifer]

Hi,
I am trying to buy a NAS. I'm beginner to this. After watching a few of your YouTube videos, I have a few questions.

Usage:
1. 2 Desktop/Laptop + 4 Mobiles + TV [1080p-not planning to upgrade to 4k any time soon]
2. Mostly for Picture, videos backups + Movie Storage
3. Watching movies/Videos on above devices

Questions:
1. Do I need transcoding? [My files are mostly in 720p or 1080p]
2. Is it better to have 2+5 Bay [DS720+ with DX517] or 4 Bay [DS920+] performance wise? I am planning to use 8TB HDDs with BTFS & SHR.
3. If I add DX517 later, do I have to increase the RAM of DS720+?

Thanks in advance

[indian9990]

Honestly, I don't think getting a 2 bay NAS + expansion bay is worth the money so I would rule that option out. It's cheaper and probably more performant to get a 4 bay NAS. For example if you have the 918+ then you'll be able to transcode and well. It gives you the greatest flexibility for further thinking.