The CPU in the DS1815 + is different from the predecessor of DS1813 + - yes with double as many cores but by the unit is not twice as fast! The number of USB ports has been reduced in this DS1815 + is now unfortunately what is a bit annoying, because according to the manufacturer Synology is per USB port also only one device manageable and not as known from Pc practiced by the use of multiple devices Usb.Hubs anschliesslich - this simply lead to a malfunction and is therefore not recommended. I personally keep my other DS1813 + due to the technical specifications instead of all to replace the current DS1815 +.