01-18-2021, 05:50 PM
You certainly would want to have some future proofing in a NAS. If you would go for value series NAS then you would need to upgrade it every 2-3 years like an iPhone. DS420+ is still a plus series NAS which means it can be upgraded and it also is compatible with all apps Synology makes. It also features Celeron CPU with graphics chip which makes it a multimedia friendly solution.DS920+ comes with 2 more CPU cores making it a better choice if you want to use it for more then just a few things. Something like Virtualization, web server would certainly make use of this extra power.When choosing the size of the drives, try to calculate how long time did it take to grow your backup to this 3TB size. Then you can predict how much more you might need in the next 5 years. But if you start with 3 drives in a 4 bay model, you can add additional drive when you need that space. Saves energy. RAID5 will loose one drive for parity/redundancy. So 3 drives will have a total size of 2 drives available (3*4TB = somewhere around 7TB).I hope this helps.