Issue with USB 3.0 Transfer speed (Locked at around 25Mb/s)

Hello everybody,

I have a strange issue with USB3 on this computer only: when I copy files to my USB3 flash disk transfer speed locks at around 25Mb/s.

I am using the fastest USB3 flash disk available "Sandisk Extreme USB3 64GB"

Even when I use the fastest USB2 flash disk "ADATA Professional Series PD7 Turbo Speed USB 2.0 flash disk" it locks around 18MB/s.

• Tests done copying 1 file around 5/10Gb
• There are no updated drivers.
• There are no USB2 devices pluged on the computer
• Tests done on all USB3 ports of the computer
• Flash disks working at max speed on other devices

This happens only on this computer, my flash disks always work at max speed on my other computers/tablets/macs and I haven't found a solution up to now for this computer.

Thank you in advance for your help.