Which one to choose for office NAS with 2 HDDs?

Question

Backup

I'm looking for a NAS in the office to use for backups.
You need a model with 2 hdd, at least 2 TB in size, 1000 MB full-fledged network interface, raid-1.
Now we use D-Link DNS-320 , but it has one drawback: the speed of both writing to it and from it is only 6-8 Mb / s, as you can see from the forums, the problem is not only with us. Replaced cables, switches - occasionally jumps up to 10 and drops again.
So I would like to change to something more nimble.

Answer 1

Hp microserver gen7 at a price of around 8000r, a gigabit adapter and a basket for 4 disks

Answer 2

Mini-ITX board + PSU?

Answer 3

Lenovo ix4-300d when connecting a computer directly to a gigabit port shows 20-33Mb / s. There are 4 screws in JBOD of different volumes.