Greetings!

I have a dedicated server in Hungary, which runs Debian Jessie ( 3.16.0-4-amd64 #1 SMP Debian 3.16.43-2+deb8u5 (2017-09-19) x86_64 GNU/Linux ).
CPU:
2x Intel Xeon Quad-Core E5620: 16x 2,4GHz
Storage:
2x120GB SSD in RAID 1
500GB SSD
500GB SSD
1000GB SSD

I would like to pay 0.03 BTC for one person who can give a solution for my problem.

Issue:
IO Hangs during copy and I got very low speed. While copy for 10sec got great speed and then for 5 sec works with 1-2MB/sec. Both SSD, so it will be some driver or configuration problem.

Some measures:
https://imgur.com/a/7B4H0

smarttcl:
/dev/sda: https://pastebin.com/4s0DV9eg
/dev/sdb: https://pastebin.com/bKLHkDmD
/dev/sdc: https://pastebin.com/Qh0QYfXg
/dev/sdd: https://pastebin.com/HdEBFWm9
/dev/sde: https://pastebin.com/1tr1WnXa

fstab:
https://pastebin.com/p8Lz6QFL
The `discard,noatime,realtime,errors=remount-ro` option was for testing.

lspci:
https://pastebin.com/0yuLqtpx

perf log files:
https://files.fm/u/pyynn22q

dmesg:
https://pastebin.com/3T723Xkh