I use 1TB WD MyPassport, connected via 2meter, double shielded cable. My firmware is: 3.0.0.4.376_1663.
'USB3.0 Interference reduction' = 'Enable' => max transfer ~19MB/s (the same HDD connected to USB3.0 port on my laptop gives transfer 68-80MB/s)
'USB3.0 Interference reduction' = 'Disable'...