Rock Pi X + Ubuntu 20.04.5 LTS as NAS

hi. Im bought Rock Pi X v1.4 with plan to use it as kind of home NAS.
I connected 2 HDD’s in ORICO Dual Bay SATA to USB3.0 External Hard Drive Docking Station to USB3 port of Rock Pi X.
I thought that it should work ok but…
Speed of USB is very very bad. about 6-7MB/sec during copying files between HDD’s.
Even 1 HDD in USB3 port has the same speed - so the issue not in the my dock station which work with Windows 10 laptop just OK.
Speed of SD-card - about 15MB/sec - I need about 2 hours (!!!) for format SD card…
Dancing with WiFi also killing my dreams to use this board as expected…
I wonder - is this board just not good for my goals and I simple was wrong thinking that it will be enough for simple sharing USB disks via some open sourse NAS software?
Or I still need to do some configuration to start it work in better way?
Please advice.
Otherwise I will put this board somewhere out of my eyes…