ExpressCard
From Wikipedia, the free encyclopedia
ExpressCard is a hardware standard replacing CardBus PC cards, both developed by the PCMCIA. The host device supports both PCI Express and USB 2.0 connectivity through the ExpressCard slot, and each card uses whichever the designer feels most appropriate to the task. The cards are hot-pluggable. This is not a free open public standard; payment is required to access the full official specifications.
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[edit] Form factors
ExpressCard supports two form factors, ExpressCard/34 (34 mm wide) and ExpressCard/54 (54 mm wide, in an L-shape) — the connector is the same width (34 mm) on both. Standard cards are 75 mm long (10.6 mm shorter than CardBus) and 5 mm thick, but may be thicker on sections that extend outside the standard form factor — for antennas, sockets, etc. The 34 mm form factor cards fit into both 34 mm and 54 mm card slots via a diagonal guide in the rear of the 54 mm slot that guides the card to the connector. The 54 mm card will only fit in a 54 mm slot.
[edit] Comparison to CardBus
The major benefit of ExpressCard technology over the previous PCMCIA CardBus PC card is a dramatic increase in bandwidth, afforded by the fact that the ExpressCard has a direct connection to the system bus over a PCI Express x1 lane or USB 2.0, whereas CardBus utilizes an interface controller that only interfaces with PCI. The ExpressCard has a maximum throughput of 2.5 Gbit/s through PCI Express or 480 Mbit/s through USB 2.0 dedicated for each slot, versus CardBus's shared 1066 Mbit/s bandwidth.
In addition, the ExpressCard standard uses lower voltages and thus less power than the previous CardBus slots (1.5V and 3.3V versus 3.3V and 5.0V).
The ExpressCard FAQ also claims other advantages, including lower cost, better scalability, and better integration with motherboard chipset technology. They also expect that the ExpressCard interface will be used on desktop computers to provide "sealed box" upgrades, which will allow smaller desktop packages and safer and easier upgrade paths for desktop users.
The ExpressCard interface is not backwards-compatible with CardBus devices, which presents a problem for those who may purchase a new system only to find that their devices do not work with the new slot design.
[edit] Availability
Hewlett-Packard began shipping systems with ExpressCard in November of 2004, [1] and Lenovo integrated the slot into their flagship ThinkPad T43 in May 2005. [2] Dell Computer also incorporates this in their Precision, Inspiron, Latitude and XPS Laptop product lines. Apple Computer included a single ExpressCard/34 slot in their MacBook Pro notebook computer in January 2006. ASUS has also replaced the PC Card slot with an ExpressCard slot on many of its new models. Fujitsu-Siemens also began shipping systems [3] with ExpressCard in June 2006. Sony also began shipping systems [4] with ExpressCard with its new laptop VGN-SZ product line. The Acer Aspire laptop series also has a single ExpressCard/34 slot.
A large number of ExpressCard devices were presented at the CeBit trade show in Germany in March 2005. [5] In November 2006, Belkin announced that it is launching the first ExpressCard docking station, which uses the ExpressCard PCIe connection to enable 1600x1200 video through a non-proprietary connector. [6] This points to the ability for ExpressCard to allow more capable non-OEM docking stations for laptop computers.
