I'm copying about 4TB of data from one hdd to another and noticing abysmal speeds.
I have two external SATA 3 hdds plugged into USB 3.0 docks and connected to USB3.0 ports on Macbook Pro. MBP was idle during the copy.
Obviously, the speed is limited by disk mechanics - according to manufacturer the read/write speed is 150MB/sec. So theoretically, 1TB should take 2hrs to copy over. I'm seeing times almost double that, which means I'm getting about 80-90MB/sec.
How can I raise my transfer speed close to max speed of 150MB/sec? 150MB/s is way below the capabilities of SATA3 or USB 3.