dell t140 low performance onboard s140 controller disk

I set up several T140 model servers and all have poor disk performance.
But I recently detected horrible performance with the Seagate ST4000DM004-2CV104 disk.
Initially tested with Linux Debian 10, but also tested with Ubuntu 18.04 which is DELL approved this disk has average speeds between 50 to 70 mb / s per second. The same disk has speeds from 170 to 190 mb / s on standard desktop motherboards.
The speed test was done using the dd command.

root @ pve: ~ # dd if=/dev/zero of=/backup/test.txt bs=1G count=1 oflag=direct
1 + 0 records in
1 + 0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 15.6891 s, 68.4 MB / s

Other disk models feature higher speeds under test. But I'm having a lot of speed complaints coming from the clients I referred to buy this server.

below tests done with ubuntu 18.04 and debian 10