Time flies, literally just 10 years ago the concept of portable storage involved a 10 pound external hard disk which could double as a space heater. The clunky RS232 cable required to hook up the device took up as much space as the drive itself. However, joyful was the mood once you engaged the power of your 10 Megabyte external hard disk on your TRS-80 Color computer. Besides, how could you go wrong with all that storage for just a few hundred dollars!
I find myself consistently surprised at the rate of micro-minaturization within the computer industry, and right now, storage is perhaps one of the best examples. As one would expect, the venerable external hard disks still exist and serve their purposes, but portability isn't really their strong suit. Up until recently, external storage meant SCSI and even in today's competitive marketplace, SCSI drives remain expensive. However the advent of "Fast USB" is turning over a new leaf. Furthermore, the proliferation of handheld devices and notebooks are propelling the PC Card market. Finally, the rapid price cuts in "Flash Memory" provides yet another possible avenue to achieving truly portable mass storage. Each kind of storage features it's pros and cons - not every device is suitable for the application you have in mind.
When you decide you need portable storage, you need to consider the application first and foremost. When buying for your PDA or MP3 player, you usually have the choice of "Flash" upgrades or PCMCIA Cards. Your typical desktop PC takes "Fast USB" these days, though many motherboards also feature "FireWire" (IEEE1394), but not PC Card support. If you're so inclined, PC Card Adapters are available for PC's.
For our purposes, we shall deal strictly with PC Cards (PCMCIA), which should be suitable for notebooks and the newer generations of MP3 players and PDA's. In particular, we will look at Toshiba's 2GB Type-2 PCMCIA hard disk.
Sometimes in the course of reviewing something, you learn a few things. In my case, I clearly did not have a good working understanding of PCMCIA bus technology. My original plan was to compare IBM's internal micro hard disk against the Toshiba PC Card, and show the speed benchmarks as a comparison. As I began testing, I was dismayed to find the Toshiba surprisingly slow in it's data throughput. The seek rate between the IBM drive and the Toshiba were identical and the rotational speed on the IBM is just a bit faster. Yet the results revealed nothing of the sort, so where was the problem?
After doing some searches on the Internet, I learned that the PCMCIA bus is limited to 16 bits at 10MHZ and therefore limited to about 20 megabits per second throughput. This stands in stark contrast to standard EIDE which can exceed 100 megabits per second when Bus Mastering is utilized. So Toshiba's PC Card could never be fairly compared against conventional drive technology.
So how does a PC Card prove itself worthy? Once again the question really comes down to the application you have in mind. If you're crunching through database queries, I would not recommend any type-2 PC Card - the technology is simply not intended for that kind of throughput. Now IBM does have "Card Bus" technology which is a 32bit based PCMCIA slot, but the adoption rate is limited and few devices support this right now. So if you need real portable speed for disk crunching access, you need to be looking towards USB or Firewire for your notebook. However, the fact is that only a few applications need high throughput. The swift seek rates are more than sufficient for general use with Microsoft Office and similar applications.