Federate issue Rostock Mini with Marlin

Hello,

I just finished to build my Rostock mini and everything seems to work fine exept the federate speed that seems much faster
then what setup in Cura or Slic3r.
Even if I set something like 10mm/s as print speed in Cura the printer is incredibly fast and the extruder sometimes
is not able to feed at that rate so I have to manually slow it down with the LCD.
Any idea of what could be the issue ?

Thanks
Piff