Does not reach the speed which I expected (around 50 mb / s at start of a transfer and then falls I'm on Windows 8.1 and is plugged into a USB port 3 (as recognized by the device manager), but surely there must be something to settle somewhere (which, in theory, should not happen ) so that the flow rate increases and is closer to what is advertised. I know we can reach theoretical speeds but it seems still low. As this was a gift (in addition to what I transfer it), I would not have the opportunity to check unless you buy one for me later ... but I'm not sure to turn around to this model (which, apart from this, even looks to me right well made).