The world’s largest hard disk manufacturer will offer customers 5% cash back on disk drives bought over the last six years in order to settle a legal action over the measurement of hard drive capacity.
But the real story starts way back when marketers decided 24 bytes didn’t mean much. In modern terms it’s equivalent to a fraction of a cent or the weight of a feather atop a two tonne truck.
It didn’t make much of a difference several decades ago when memory capacities nudged past the three-digit mark and it was decided that a ‘kilobyte’ – based on the established use of kilo as meaning ‘a thousand’ – would be useful shorthand for 1024 bytes. After all it was just 24 bytes right? Of course it followed that there’d be a thousand kilobytes in a megabyte and so forth.
Warp ahead to the modern era of gigabytes and terabytes and that molehill became a mountain as physical capacity set on a decimal-based definition of 1000 units fell behind the binary-based assumption of 1024 units.
By the time we hit one gigabyte the difference between was 73MB. 10GB disk drives had a usable capacity that fell 730MB short of the promised ceiling (in fact this was more that the operating system reported and dealt with the drive capacity as the smaller figure but the end result was the same). 100GB drives had some 7.3GB missing in action while 500GB drives shortchanged customers by 35GB and put only 465GB on the platter.
This discrepancy vexed Michael Lazar and Sarah Cho two US purchases of Seagate drives who in 2005 initiated what became a class action suit against against the company. They claimed that the company mis-labelled hard drives with the higher capacity which they say amounted to a misleading promise that customers would receive approximately 7% more usable storage capacity than they actually received.
Seagate this week settled the case by offering customers a cash payment equivalent to 5% of the drive’s purchase price or a “free backup and recovery” program. The caveats? You have to have purchased the drive “from an authorised Seagate retailer or distributor” between March 22 2001 and September 26 2007. Buying a desktop laptop server PVR or other non-Seagate product with a Seagate drive fitted doesn’t count.
Oh and you had to have bought it in the US. Yep this deal is stamped ‘For Yanks Only’. You’ll find full details here if you’re interested.
This settlement comes with potential implications for customers in other countries and other hard disk manufacturers for that matter. Seagate has long been specifying in the fine print of its retail boxes that actual capacity differs from the stated capacity – which also takes into account the overhead added by formatting and the way that operating systems might report the disk capacity (which can in turn be affected by the size of each block in the file system versus the size of files being written to the disk).
There’s also a movement to popularise use of the terms mebibyte and gibibyte (respectively contractions of ‘mega binary byte’ and ‘giga binary byte’ and abbreviated to MiB and GiB) as binary-based units of computer storage.