Running into issues with Plex/Nas

[Enquiries]

Good evening,
I have watched many of your videos. I am trying my best to figure it out myself but I am struggling. I cant seem to get Remove Access to work properly. I realized my Nas can not support Plex. Though I can put it on the NAS, it seems to be super slow. My NAS is the following:
Model: DS1512+
CPU: INTEL Atom D2700
CPU Clock Rate: 2.13 GHz
CPU Cores: 2
DSM Version: 6.2.4
Total Physical Memory: 4096 MB
I believe I have 4 GB Ram.
Now, I am also trying to play 4K from the NAS and it is VERY inconsistant when and how it plays. Some have played fine but others seem to bog down so much. The hard drives I am running are QTY 5:
Seagate ST6000VN0033-2EE110.
I ensure I purchased all the same. All the drives appear to be healthy. My CPU tends to also run and jump to 99%.

I dont know what I am doing wrong or what I need to do different. But it does not seem stable. I have already had one of my Volumes crash on me once before. I have not set up a back up yet because I do not understand how to do so. I would like to do one with a USB function so I can put it in my safe after back up in case of a terrible event.

[ed]

Your NAS is very old. It can not stream 4K remotely. Or even locally on non 4K TVs. If TV support that video type and encoding, you can stream the original file even with old NAS.
But otherwise, you will need to get something much faster such as ds1621xs+ for 4k remote streaming in Plex. Or Qnap 674 with core i5 inside.
Or get DS920+ / ds1520+ that can stream 4k remotely via Synology video app instead of Plex.

I hope this helps.