The ExpressCard, not to be confused with the card of the “don’t leave home without it” variety, is actually the successor of the PC Card, or PCMCIA card, as it was known. PCMCIA actually stands for the organization that developed the standards, which is the “Personal Computer Memory Card International Association,” and not “People Can’t Memorize Computer Industry Acronyms” as it has come to be known.
The ExpressCard standard, which replaces the older CardBus, was developed to bring the high speed, flexibility, and lower cost of the PCI Express (PCIe) and USB 2.0 interfaces to laptop computers. Theoretically, ExpressCard will have a maximum throughput of 250MBps (megabytes per second) for data transfer (500MBps total: 250MBps to the computer in one direction and 250MBps to the card in the other). This is in comparison to the 132-MBps PC Card standard. ExpressCard’s throughput is ideal for video transfers and uncompressed files. To compare it with other throughputs: Gigabit Ethernet has a throughput of 125MBps, FireWire 800 (seen only in new Apple notebooks so far) runs at 100MBps, and USB 2.0 can reach 60MBps. The ExpressCard comes in two sizes, one 34mm wide and the other 54mm wide in an “L” shape. Another advantage of the ExpressCard, aside from lower system and card complexity, is their ability to be hot plugged.