This series explains connectivity options for CAD hardware. The first post covered network connections and USB. Now we'll discuss PCI, FireWire and eSATA.
Yes, the old standard PCI add-in card is still around, and from a user's perspective is completely different than PCI Express. A PCI slot can't support a PCI Express card, and vice versa. However, workstations will still include a PCI slot or two for low-demand legacy cards. Unless you have some special legacy PCI requirements, you're unlikely to be disappointed by whatever your OEM provides.
In the age of first-generation USB, FireWire (also known as IEEE 1394) was pretty much a requirement, as USB's bandwidth was too wimpy to handle video. That changed dramatically with USB 2.0, which more or less matched FireWire in performance.
At this point, if you plan to keep a legacy device that requires FireWire — and check it out closely, as many devices that support FireWire also support USB 2.0 — then of course make sure your machine has a FireWire port (and you can always add a PCI or PCI Express card).
Most modern workstations also include an eSATA connection, a high-speed computer bus interface that connects host bus adapters to mass storage devices such as hard disk and optical drives. With USB 2.0's advance in speed, most of us just naturally opt for USB to accommodate external storage. And with USB 3.0 on the horizon, it's hard to see what use eSATA will serve in the longer term, beyond supporting legacy devices.