[userbinator]

From what I understand these could be 320GB drives that were rejected because they had too many bad sectors, but still had over 314GB of usable storage. Manufacturers usually don't, but they can definitely control in firmware --- down to individual sectors --- how much usable capacity a drive has. A drive that didn't make 320 would likely be cut down to 250. They don't do it more granular than that because it would either mean a proliferation of models of very similar capacities, with the associated complexity of stock-keeping, or they'd have to sell drives where e.g. 320GB would mean a guaranteed minimum and you might get a 321, 325, or 323GB unit. (The early PC hard drives that came with a list of bad sectors physically printed on them were like this --- some would have more, and some would have less, but they'd all be within a few KB of a "nominal" capacity.)

I wonder if they made this one exactly 613,592,315 sectors...

[Laforet]

Years ago WD sold a 808.8GB drive which reportedly contained two 500GB platters that had failed QC.

http://www.newegg.com/Product/Product.aspx?Item=9SIA67S23Y89...

[trengrj]

It always scares me when buying smaller than normal hard drives in that I am actually just buying drives that have failed QC.

[beeboop]

Hope you never buy anything other than the fastest GPU and CPU for a given model :)

[chiph]

But they passed the 2nd QC check, so all good!

[makomk]

I think a lot of Flash-based storage devices still work like this - the exact number of blocks they expose depends on how many defects the particular dies happened to have.

[Laforet]

I am not sure if this still done with NAND memory - unit cost is low enough that they seem to just dump the bad examples or worse, off load them to dodgy buyers who make those offbrand novelty flash drives sold on ebay.

[drudru11]

Not just hard drives, but CPUs are sold like this as well.