Aaron Adams’s Blowhard Blog

Contributed by reader kingstud

After reading Aaron’s debacle regarding the iPod Shuffle not being consistent with the true amount of space available on the device, it caused me to think of a subject that frequently irks me.

First, a bit of history is required. As most of you should know, computers are currently a binary system. Therefore, numbers tend to get represented in power of 2. Because of this a Kilobyte is 2^10 = 1024 bytes. Yes, that’s right folks, despite one’s desire to force the metric system into computing, a “K” in computers generally is an abbreviation representing 1024 - not 1,000.

The problem arises when you, the consumer or user, gets cheated. For example, hard drives manufacturers tend to measure their drive capacities in power of 10, meaning 1K = 1000 bytes. Yet, operating systems nearly always use the power of 2 representation that 1024 bytes = 1K. You are getting ripped off to the tune of roughly 2.4%. That’s why, when you buy that supposedly 40 Gigabyte hard drive, the BIOS, upon boot shows the drive usually containing a scant 39 Gigabytes of capacity.

Cheating you on capacities is not a practice reserved for hard drive manufacturers. In fact, nearly every solid-state storage device uses power of 10 to represent capacities. Yet, RAM, network cards, or nearly anything other than solid-state storage is sold with powers of 2 based capacities. When one purchases a 100 megabit per second networking card, that capacity is represented using powers of 2. Likewise, when one purchases RAM, say 256 MB, that is also represented in powers of 2.

The problem arises when programmers try to keep track of it all. Naturally, even though most programmers are zen-like in their attention to details, mistakes are understandably made from time to time. Incorrect assumptions are made, and you, the consumer, has to deal with problems akin to the one Aaron experienced.

As Aaron said, let’s just be consistent. If the device says x amount of space is free, I should be able to fit a file that large in the space, regardless of file system overhead, etc. I personally don’t care about losing 2.4%, but I do care when my experience as the user suffers.