I have a mid 2013 Macbook Air with blazing fast 256gb ssd and a 2011 Mac Mini Server with a 512gb crucial mx100 ssd and a 2tb m9t hdd. Both running Yosemite 10.10 Using Blackmagic Disk Speed Test the Macbook Air hits around 680MB/s write and 700MB/s read. The Mac mini ssd hits around 480MB/s write and 500MB/s read. I connect them via Thunderbolt and restart the mini in target disk mode. When sending files from the Air to the mini ssd the speeds average around only 150MB/s. Is this normal? What sort of speeds are other users getting in similar ssd to ssd transfers? I've tried varies sizes and types of files with similar speeds. I had really expected the transfer speeds to be approaching 300MB/s. Am I right in thinking thats the sort of speeds that should be possible? Whats causing the slow down? is this really as fast as target disk mode gets?