ExpressCard: A Sure Thing That Failed

PCMCIA and CardBus slots were universal and popular a decade ago, but the advent of PCI Express meant reengineering the old standby. The result was ExpressCard, a never-popular compromise that mixes PCI Express and USB into a confusing and little-used mashup. With few modern laptops including an ExpressCard slot and fewer users, a fair question to ask is “where did it all go wrong?”

PCMCIA/CardBus and ExpressCard: Handing Off the Baton

The CardBus spec was a mess, but consumer demand forced manufacturers to make it work. By 2000, nearly every laptop had one or more CardBus slots and electronics retailers stocked a wide variety of expansion cards, from mundane modems and Ethernet adapters to exotic SCSI controllers and video cards. Though still widely referred to by its caveman-era name, PCMCIA, expansion cards were good business.

But market forces were about to collide with PCMCIA/CardBus:

1. Computers were transitioning from parallel PCI to serial PCI Express internally, and it made less and less sense to cling to a PCI-based expansion card format in this new era.
2. USB 2.0 offered “good enough” performance and unbeatable pricing for simple connectivity of hard disk drives.
3. Laptops began integrating more features, including modems, wired and wireless Ethernet, and better video cards.

ExpressCard was meant as a natural successor to CardBus. It included PCI Express, offering better performance and (optionally) a smaller form factor, and even leveraged USB for less performance-oriented requirements. ExpressCard slots were offered in two sizes: a stair-stepped 54-mm card like the old PCMCIA standard and a narrower 34-mm option that matched the new physical connector.

Inside that hot-pluggable connector is both a single PCI Express lane and a USB 2.0 channel, allowing peripherals to use either means of connection. In practice, the majority of ExpressCard peripherals use USB alone, including memory card readers, 3G WLAN adapters, and SSD drives. The main exception is eSATA controllers, which typically use the PCI Express lane for better performance.

Where Did ExpressCard Go Wrong?

ExpressCard looked like a sure thing, offering features for both the performance-sensitive high end and price-conscious low end of the market. But something funny happened next: By the middle of the 2000’s, just as ExpressCard began to become common, laptops began losing their card slots altogether. The hyper-competitive laptop market had changed, with integrated chipsets including most popular features and consumers loathe to spend more for potential expansion.

This lack of uptake, in turn, derailed the marketplace of ExpressCard peripherals. The bulk of CardBus sales were network adapters (now included by default) and modems (now passé). The remaining expansion market niches were simply not all that exciting. USB memory card readers were cheap and popular, so USB-based ExpressCard readers were not really compelling. The same can be said of USB-based ExpressCard WLAN adapters. The few buyers of ExpressCard SSDs were disappointed as well, since their expensive flash storage was invariably backed with a slow USB connection. And not all that many people really wanted an eSATA port, the only real remaining market.

So ExpressCard was killed in two ways: Its inclusion of USB backfired, destroying its performance-oriented differentiation from plain USB peripherals; and consumers simply didn’t want to expand their laptops with peripheral cards anymore. Now, with USB 3.0 on the horizon, one wonders whether ExpressCard 2.0 will ever take root at all. Laptop makers are increasingly integrating features like memory card readers, WLAN, and SSD, further destroying the market for ExpressCard.

Stephen’s Stance

The demise of ExpressCard is disappointing for computer enthusiasts, but average computers users never noticed it in the first place. Their needs are met with integrated features and USB ports, and they would rather have a smaller and cheaper laptop than an expandable one.

But I, for one, am glad that my MacBook Pro includes an ExpressCard slot, and Apple’s decision to remove it from the 15″ model is holding me back from upgrading. I wish my iMac included some sort of expansion capabilities as I ponder adding eSATA. The demise of high-speed expansion slots limits the ability to use computers to their fullest, and I hope internal PCI Express slots don’t suffer the same fate!

ExpressCard diagrams by en:User:Henriok