在 apple support communities 中有人提到 usb HUB 如果是由電腦供電,可能會有停滯的現象。 所以最好的作法是不要再開機的時候接上 usb hub 但它也提到這可能是特定型號的 usb hub 才會有的狀況。 身邊沒有其他具備 USB 3.0 介面的設備。不然應該可以能去測看看。 以下是回復的原文。 Don't connect a hub while booting the Mac.
Apparently the USB3 architecture behaves like the old SCSI and Firewire busses of old, where the slowest device would set the pace for the entire bus. And the USB3 hubs appear to bog down when buspowered. May truly be something standard with USB3, or simply the behavior of a brand/model in particular.