What Is an Express Card for a Laptop?
By Maxwell Payne
To reduce weight and size of laptops, manufacturers are always looking for ways to make laptops smaller and lighter. An ExpressCard slot allows various ExpressCards, each that serve a different function, to be inserted into the slot when needed and replaced with another card when another type of port or function is needed. Multiple ports, in essence, can be combined into a single ExpressCard slot.
ExpressCards were developed as an enhancement of older PC Card technology. ExpressCards are lighter, less complex in their design and less expensive to produce. They are also about half the size of PC Cards. The ExpressCard standard was developed by the PCMCIA Association, including companies like Dell, HP, IBM, Intel and Microsoft. ExpressCards support USB 2.0, PCI Express and SuperSpeed USB applications. Their serial data interface supports a data transfer rate of 2.5 Gigabits per second. The 26-pin connector in an ExpressCard is designed to last for at least 10,000 card insertions and removal cycles.
ExpressCard Form Factors
The two standard ExpressCard formats are the 34mm and 54mm cards. The measurement that each type is named after is the width of the card. The ExpressCard slot on a laptop may either be an ExpressCard/34 or an ExpressCard/54, with each number representing the width of the slot. The depth is always 75mm and both form factors use the same connection interface.
For laptops, size and portability is an issue. Laptop makers attempt to fit more and more components into smaller laptops, and an ExpressCard slot can help in this process. Since ExpressCards come in a wide range of functional adapters, a computer manufacturer can include an ExpressCard slot on a laptop instead of extra ports or internal cards. ExpressCards are designed to be hot-pluggable, meaning you should be able to remove and insert different cards without having to restart your computer.
While an ExpressCard/34 slot may save a little space, an ExpressCard/54 slot on a laptop can offer a wider range of uses. This is because the makers of ExpressCard slots designed the 54mm slot to accept both 34mm and 54mm cards while the 34mm can only accept the smaller sized cards.
An ExpressCard is not an SD card or microSD card. It is also important to note that a PCMCIA card is longer than an ExpressCard. Older PC Cards will not work with an ExpressCard slot and ExpressCards will not function with PCMCIA or CardBus slots. The connection end on PC CardBus and PCMCIA cards is wider than ExpressCards, making them incompatible with ExpressCard 34 or 54 slots.
Maxwell Payne has been a freelance writer since 2007. His work has appeared in various print and online publications. He holds a Bachelor of Science in integrated science, business and technology.