When You Say 500GB, You Mean…?

While working on my new laptop (a post is forthcoming…), I installed a new hard drive in a bay adapter. I got the 500GB Western Digital Scorpio Blue (5400 RPM, SATA 3Gb/s transfer rate, 8MB buffer) for $115 at Amazon.

I mounted the drive into the adapter, plugged it in, created a partition, formatted it – and was left with 465MB of free space.

My first thought was WTF?! Where did 35GB go? I checked the HD’s property page, and the Vista “partition tax” (amount of disk space the OS uses to manage the partitions file allocation table etc.) is 104MB. While stiff, it didn’t account for the entire lost space.
It all stems from the little scam HD makers run on us:
Every little kid who ever handled any computer equipment knows that storage units are measured in powers 0f 2. 1024 bytes per KB, 1024KB per MB, 1024MB per GB, 1024GB per TB etc. HD manufacturers, on the other hand, use 10-base numbers (1000).

Thus 500GB for Western Digital is actually 500 * 1000 * 1000 * 1000 bytes. Divide that number by 1024 * 1024 * 1024 and you get 465.66.
So, whenever you purchase an HD, look at the promised capacity, and subtract 7% (multiply it by 0.9313 == 1000^3/1024^3) to get the actual capacity. And then subtract whatever “partition tax” your OS levies (for which the manufacturers cannot be blamed).

I wrote about this scam before (see item 1), but it seems like the lawsuit against Seagate did not deter anyone. At the bottom of the product page, WD provides some @$$-covering lingo:

As used for storage capacity, one megabyte (MB) = one million bytes, one gigabyte (GB) = one billion bytes, and one terabyte (TB) = one trillion bytes. Total accessible capacity varies depending on operating environment. As used for buffer or cache, one megabyte (MB) = 1,048,576 bytes. As used for transfer rate or interface, megabyte per second (MB/s) = one million bytes per second, megabit per second (Mb/s) = one million bits per second, and gigabit per second (Gb/s) = one billion bits per second.

Dear Western digital: the fact that you spell out your scam, does not absolve you. Why not just sell a 465GB HD instead?

My only question to WD is: next time I purchase any of your drives, can I pay you 93 cents on the dollar?

PS: this post was written in 30 minutes. Each minute contained 52 seconds… :)