Samba slow transferrate vs OpenElec

[Jumento]

Yesterday i received my Raspberry PI 2 and i have installed it with Xbian and OpenElec for testing purposes.
With nothing configured i get a very slow transfer rate on Xbian when copying data via cabled network to my attached USBdisk via Samba compared to OpenElec. With the Xbian install the highest transferrate is around 700Kbps while with OpenElec the least i get is around 2/3 Mbps.

Does anyone recognize this behavior? With the previous model i was experiencing the same differences in the transferrate. Is there any solution for a better transferrate with the Xbian install?