LSI SAS2308-IR poor performance

I installed on the workstation, Win10 64bit pro on 4 Hdd Seagate Barracuda 750GB ST3750330AS 3Gbps connected to the SAS2308-IR controller and configured in Raid10. I waited for the complete initialization of the Raid10. By copying big video files to and from the Raid10 Virtual Disk, I got unexpected performances: maximum transfer speed around 75MB/s.

I also tried to install Fedora Workstation 28 64bit to repeat the test of data transfer speed to and from the Virtual Disk Raid10: results more or less similar.
To check if the problem is on the LSI 2308-IR controller I installed win10 pro 64bit on an HDD Seagate Barracuda 2TB ST2000DM001 (I did not use one of the previous hdd to not destroy the raid10) connected to the Sata0 of the Intel C602 chiset. In this case the video file copy to and from the disk has obtained much higher speeds, well over 100MB/s.
Currently the revisions of Bios and Fw are:

MB 158B Bios V. 3.94;
LSI 2308-IR MPT2BIOS 7.35.02.00 (2014.03.12), FW 18.00.00.00-IR, NVDATA 11.00.00.08;
ST3750330AS FW V. SD1A

Looking on the web I saw very different results for similar hardware configuration:

https://www.anandtech.com/show/6228/asrock-x79-extreme11-review-pcie-30-x16x16x16x16-and-lsi-8way-sassata/10

Thank you