Compared with standard hard drives, external hard disk has   a drawback, and sometimes the problem of insufficient power supply will appear, if this happens, how do we solve it?

(1) Purchase a better usb external hard disk box.
(2) Purchase a 4200 rpm notebook hard drive, using it as external hard drive. Do not buy a 5400 rpm. Do not believe the electric current value written on the hard disk, there is no reference value.

(3) When purchasing a laptop, you should consider the capacity of usb port power supply. These Usb port power supply capability has been proved too weak: Samsung Q20 / dell 300m/X300; sony V505; IBM R40 prior to almost all R; toshiba P2000/2010 … usb power supply capability is poor, more common in Japan and South Korea Department of thin machine. The best is the IBM X31′s usb port, regardless of external hard disk (even if it is 5400 rpm); external combo all-take-all, its power supply capacity is not inferior to the general PC. If you buy a usb2.0 card pci, you should pick a 4-pin auxiliary power supply port; if used to purchase laptop pc card usb2.0 adapter, you should pick an auxiliary power supply transformer, at least pick one  with a ps2 auxiliary power supply lines.

(4) external hard disk box also has its own auxiliary power supply lines, good box directly has a transformer, poor box also has a ps2 or usb power lines, of course, you should plug in it when the power supply is insufficient, even if the usb port driven hard enough, if not short – time work, it’s proposed to plug in, usb power supply is always very reluctant.