[Solved] RAM and low network speeds

Hello, i have a problem with my new microserver g8 G1610T 4GB RAM.

I have two Seagate Ironwolf 6TBs in a raid 1 configuration installed.
Writing to them through the network is no problem, full gigabit speeds.
Reading starts with full speed, fills up the RAM in no time and the speed drops to 50MB/s max.
The cpu is nearly idleing.
The hard drives deliver full 240 MB/s, why is it using the RAM cache and why is it then dipping down to these low speeds?
Trying SFTP instead of SMB and tweaking some settings did not change anything.

What could be the problem?
Thanks in advance

Or is my CPU underpowered and it just doesn’t correctly show at the graph?
What are the main requirements for delivering Gigabit speeds?
Where is my bottleneck?

Try nfs or just a scp copy. underpowered CPU would definitely slow the smb copy. If you want. Try some samba options from some how to articles. Substitute centos 7 for rockstor when searching.

Thanks a lot, but i now found out, it was a client side issue (didnt think of it with only ssds on the client)