Express Cards – What are they & why are there two sizes (34mm & 54mm)

If you’ve purchased a new laptop PC latelysmaller systems, the slightly wider 54mm Express
you’ll probably have noticed a new looking slot onCards can support applications that would not
the side of it. This is the Express card slot.physically fit into the a narrower 34mm Express Card.
ExpressCard technology has been designed to deliverExamples include Compact Flash readers, and 1.8-inch
high-performance (they support faster data transferdisk drives both of which are wider than 34mm.
with lower power consumption) and allow modularAdditionally the 54mm Express cards give a little more
expansion to your laptop. If for example you’veroom for on-board components which in turn reduces
purchased a laptop without a Firewire port but youthe amount of heat generated – sounds incredible
then find you need Firewire to transfer video frombut the slight larger card does allow for the heat to be
your Camcorder you can add Firewire capabilities withdissipated more efficiently which can be important for
a Firewire Express card.some high performance applications
 After a slow start there are now lots of Express
There are two standard formats of ExpressCardCards on the market to allow you to upgrade your
modules: Laptop and these include:
1. 34mm ExpressCards (size:34mm x 75mm)- eSATA Express Cards
2. 54mm ExpressCards  (size: 54mm x 75mm)- Firewire 400 Express Cards
Both sizes are 5mm thick, the same as the PCMCIA- Firwire 800 Express Cards
cards they replace. Both sizes of card use the same- USB 2.0 Express Cards
connector interface – so the “business end”- Solid Storage Express Cards (up to 32GB of
which actually connects internally inside the laptop isstorage)
34mm wide whichever size express card your laptop- Serial Port Express Card
supports. This is possible because the larger 54mm- Parallel Port Express Cards
Express cards are manufactured in an “L”- CF Card Readers
shape with what looks like the corner cut out to enable 
the interface end to connect internally.USBNow carry a wide range of express cards and
Why two different sizes? Well, it’s to give theare always happy to offer any advice and guidance if
system manufacturers greater flexibility than in theyou have a particular requirement.
past. While 34mm Express Cards are better suited to