Acomdata External HARD DRIVE USB 2.0, User Manual

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number of files being transferred, and; the speed at which
other devices can transfer data to/from the Drive. Also, as is
the case with any data I/O (input/output) technology, some
bandwidth is taken up by the protocols that structure and
govern data transmissions—this is called interface overhead .
Given these and other factors, in day-to-day use you can
expect to get maximum, sustained transfer rates in the mid-
30s MB/s (Mega
bytes
per second).
Note: The interface transfer rate specification of an I/O technol-
ogy, such as USB, is expressed using the
bit
as the base unit (e.g.
Mbps) because this is the truest way of measuring raw interface
performance. However, for the end user it is more meaningful to
express day-to-day transfer rates using the
byte
as the base unit
(e.g. MB/s) because computer files are measured in bytes (kilobytes,
megabytes, etc.).
USB 2.0 is backward compatible with USB 1.1. This means
you can connect a USB 1.1 device to a USB 2.0 port, and vice
versa. However, interface transfer rates are limited by the
interface with the lower bandwidth. So, for example, if you
plug a USB 2.0 device into a USB 1.1 port on your computer,
data transfer rates will be limited to USB 1.1 speeds.
USB uses a master/slave architecture. This means the com-
puter (the "master") dictates data flow to, from and between
attached USB devices (the "slaves"). A single USB bus can