RB2011 Low Performance on Gigabit switch

Hello,

I’m totally new with Mikrotik and RouterOS. I just bought RB2011UAS-2HND-IN and did basic setup. So far only default firewall rules and no VPN.
I connected NAS and some desktops to gigabit switch (using same hardware and sam cables like with old cheap router) and noticed significant drop of speeds.

I already dig the forum and google and only tip which I found is disabling LCD which I did - it’s helps a lot but still I’m facing performance issue.

My tests showing:

Old cheap gigabit router:
NAS ↔ PC transfer rate at 110MB/s
NAS smb share to smb share from PC level transfer rate at 50MB/s

RB2011UAS-2HND-IN (after disabling LCD):
NAS ↔ PC transfer rate at 60-100 MB/s (very often not stable)
NAS smb share to smb share from PC level transfer rate at 25-35MB/s

Any ideas what can I change, tune, etc?

I have same problem in CRS 125, I solved this problem by enabling master port