User Manual

Using Your Notebook 3
65
Dimensions of ExpressCard
Current CardBus PC cards are 54 millimeters wide. ExpressCard can divided
into two categories, based on width. Most designs will use the ExpressCard 34
design, which sets the width at 34 millimeters. For some applications, the wider
ExpressCard 54 standard will be used to produce cards that can handle the
higher thermal requirements of those applications.
All ExpressCard modules are 5mm thick but the standard also allows for card
developers to build longer 'extended' modules.
Native Bus Connection
The ExpressCard standard supports both the USB 2.0 and PCI Express
interfaces. Card manufacturers are able to choose whichever bus is appropriate
to their application; the performance of PCI Express, or from the wide range
of solutions supported by USB. All host PC ExpressCard slots will support
cards using either interface. The host platform no longer needs to incorporate