Copying to USB drive is too fast? (vm.dirty_background_ratio, vm.dirty_ratio have no effect)

Hello!

Just finished configuring my PC - XFCE4 + latest linux-lts kernel.

Problem:

Copying files to USB stick is too fast - only visually

After the copy dialog is closed, the USB stick is still in use... (also if I try to eject the USB stick it takes ages...)

I've tried to change the:

vm.dirty_background_ratio & vm.dirty_ratio to lower values but there is no change...

I used this trick long time ago and it fixed the issue but is not working anymore...

Any idea on how can i see the actual copy speed?