What brand of mobile hard disk is better? Which brand of mobile hard disk is good?

What's dominant mobile hard disk Seagate and Western Digital or not these two big brand camp it?

Today on the relevant system Daquan what brand of mobile hard disk is better?

System Daquan for mobile hard disk which brand is better to collect a lot of relevant data sharing on the Internet.

Mobile hard disk believes that everyone will not be unfamiliar, similar to ordinary hard disk, but mobile hard disk emphasizes portability of large-capacity storage, so mobile hard disk uses USB or IEEE1394 and other fast transmission interface, you can Higher speed and data transmission with the system.

It can be said that the mobile hard disk is an upgraded version of flash memory products such as U disk and disk, which is widely accepted by the public. Then, what are the brands of mobile hard disk and the ranking of brand sales?