Musing about hard disks

The first time I held a hard disk in my hands–well, a removable device that contained a hard disk–was around 1977, when we installed a Datapoint multiterminal system in UC Berkeley’s serial processing department. (I wrote the timesharing monitor and data entry software and oversaw the system; that’s indirectly how I met my wife, so I count it among my greatest successes.) The removable disk was a 12″ round Winchester cartridge, maybe two inches tall (my memory is vague), and I believe each cartridge cost several hundred dollars. I believe it held 10 megabytes, but it might have been 40. It was a well-priced miracle, as was the Datapoint in general (running three terminals off a “minicomputer” that was a Z80 at 2MHz with 128K RAM, but also with Datapoint’s remarkable Databus operating system and ARCnet network).

If you had suggested to me at that point that I would some day not only use but own a one terabyte hard disk system, I would probably have laughed (you might have had to explain what a terabyte was first).

Coming forward to 1984-1986

I started writing what became “Common Sense Personal Computing” in Library Hi Tech in 1985, and published Common Sense Personal Computing: A Handbook for Professionals in 1986. In the first article in that extended series, I tried to suggest comparable system prices for a variety of personal computers, an interesting task since so many computers at the time were priced without needed peripherals. The article was based on June-July 1984 prices: that was when IBM dropped its prices by about 25% and Apple “finally dropped the IIe price to a plausible level.”

If you’ve forgotten or are too young to remember PCs in 1984, many of them didn’t have hard disks at all–including the IBM PC itself, which sold for $3,000 to $4,000 once you included a monochrome monitor and two 360K diskette drives (along with a 4.77mHz 8088, 128K RAM, a display adapter, and a dot matrix printer). That IBM PC ran “PC-DOS,” IBM’s version of MS-DOS–and cost just about the same as an Apple IIe + CP/M card ($3,000 to $3,600 with a 1.25mHz 6502, 128K RAM and two 140K diskette drives, an Apple monitor, Gemini dot matrix printer and some software–but a chunk of that money was for the “CP/M card,” a more powerful Z80A computer on a card with its own RAM). Remember the early Compaq “portable” computers? $3,500 to $4,000 for a 4.77mHz 8088 with 128K RAM and a built-in 9″ monochrome screen–and, yep, two 360K diskette drives.

Ah, but I did have two systems that make it possible to estimate what a hard disk actually cost. The Morrow MD2 with 4mHz Z80A, 64K RAM, two 184K diskette drives, 12″ display, the Star Gemini dot matrix printer I was quoting as part of most of these systems and a whole bunch of high-quality software (WordStar, LogiCalc, Correct-It [back then, spellcheckers were separate programs], Personal Pearl database, PILOT and two BASICs) cost $1,460 to $1.720. But there was also the Morrow MD11 (my second PC, actually), which differed in two ways: It had 128K RAM…and it had a huge 11MB hard disk (and a single 360K diskette). It also cost $3,300–at least $1,600 more. I’m guessing that at least $1,000 of that was for the hard disk. So let’s say $90/megabyte for a slow internal hard disk in 1984.

By 1986, you could buy an internal 20MB hard disk for as little as $600, although most name-brand drives went for $800 or more; an external 20MB drive would run around $900. So let’s say $30/megabyte for internal, $45/megabyte external. (At that point, ads for IBM PCs showed around a $400 differential between those with 10MB hard disks and those that had two diskette drives, or $40/megabyte.)

By 1989, you could buy a Seagate ST251-1 40MB drive for $439–internal disks were already down to $11/megabyte.

Remember, these are megabytes. A 1TB drive has the same capacity as 25,000–twenty-five thousand–40MB drives.

(Almost since the beginning, hard drive capacities have been quoted in decimal form. A 1TB drive is “actually” about 930 gigabytes, if by “gigabyte” you mean 1,024 megabytes, where a megabyte is 1,024 kilobytes and a kilobyte is 1,024 bytes. And of course there was at one point a class action lawsuit over the “missing” capacity in hard disks.)

Here it is almost 2011…

OK, admittedly this was a Black Friday price, but still: Western Digital WD Elements 1TB Portable Hard Disk, WDBABV001BBK. One terabyte of NTSF-formatted disk space with a USB 2.0 connector, powered by the USB port (no power cord or external power supply). 5400RPM. No bloatware, so you get the full 1TB.

At Target. $69.

The beast is 3″ wide, 4.4″ long, 0.7″deep. Amazon says it weighs 12oz; I’d have guessed a little lighter. It came in the best packaging I’ve seen for this kind of device: Cardboard box not much bigger than the drive, two tiny plastic protectors at either end, and a plastic bag–probably less than an ounce of packaging, and both the cardboard and the little protectors are recyclable. The high-security seal? A peel-off circle. No muss, no fuss, one minute to open and one more to install.

It’s sitting here on my desk (I did a full image backup yesterday: took maybe half an hour; Windows7 includes System Image Backup software in all versions; now I only have 850GB available). It’s a cute little box. And it has ONE TERABYTE of storage. Which cost me $0.0757 per gigabyte or .00757 cents per megabyte, if you include sales tax (9.75% here). Oh, and Target printed out a $10-off-on-$100-purchase coupon, good for the next couple of weeks, so you could say this only cost $65 including sales tax. That does include the case and the circuitry for USB-powered operation.

I dunno. Maybe I’m getting old. This seems like a miracle. It’s also, to be sure, a whole lot more disk space than I’m likely to need unless I start doing a lot of photography or video editing–I mean, if I wiped out all the Windows checkpoints, I’d probably have 175GB free on my 250GB notebook hard disk. (All of my data files, excluding the MP3 files I could always rerip from CD, fit quite nicely in a 3.7GB backup on an 8GB flash drive. Text and spreadsheets just don’t use much storage space.)

But there it is: in 21 years, the price for hard disk storage dropped from $11/megabyte to $0.000757/megabyte. Put another way, 11 years ago disk storage cost 145 thousand times as much as it does now.

But that’s wrong–in two ways

It’s wrong first because portable (USB-powered) hard disks are inherently more expensive than wall-powered external drives and internal drives.

My brother was at the same Target a couple of hours earlier. He picked up the last of 39 Western Digital 2TB external hard disks. For the same price: $69 (not $69.99, but $69). So he was getting storage, including tax, for less than four one-thousandths of a cent per megabyte.

Yes, those are Black Friday prices–but a quick look online shows that you can buy a WD external 2TB hard disk for as little as $89, or a higher-speed 1.5TB internal hard drive for $70 (all drives are Western Digital for consistency, and the $70 is from Amazon)–so that’s somewhere between 4.4 and 4.6 cents per gigabyte, or less than five one-thousandths of a cent per megabyte.

It’s also wrong, of course, because you can’t buy a one-megabyte drive for five one-thousandths of a cent or a one-gigabyte drive for a nickel. The cheapest hard disk I found at Amazon was $37, an 80GB 7200RPM Western Digital; Fry’s had nothing under $40. Basically, you’re still going to pay $30 or more for an internal drive and probably $40 or more for an external drive.

Still, it’s amazing to think of a price change of 140,000:1 in just over two decades–for a disk that’s probably quieter (it seems to be silent) and faster than that 40GB disk was in 1989.

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