Hi, If anyone could help me out that would be great. Basically I have a network shared SMB server (NAS), via gigabit LAN. I have recently moved from a windows machine to a retina iMac and the exact same cable plugged into the NAS got me full gigabit speeds. For some reason on OSX I get half of what it should be. I've tried changing MTUs and other things but not joy. So the EXACT same configuration on the RiMac halves my transfer speed to the NAS? Any ideas please on what this could be. Thanks.