Gemäss Mikrotik soll es eine Leistungsverbesserung bringen o-ton: "Many MikroTik Routerboards are equipped with a micro SD card reader. This card reader is a great solution to expand the Routerboard's internal storage. It's also very interesting that many Routerboards will write data significantly faster on this card than on their own internal storage."
und aus dem forum: "memory on all Mikrotik devices is primarily for data bases of RouterOS, logs, skins for hotspot etc. It is not for SMB or NAS purpose, as its not fast nor has ROS the services to do that. If you don't know what you could use it within ROS then you won't need it."

hmmm :)