datahoarder

It’s technically possible, if the drives were binned. Not likely, but possible.

Binning is a process where manufacturers take large drives and artificially reduce their size. Let’s say a company makes 1TB drives, but their manufacturing process only reliably works for 2/10 drives. They test each drive, and 8 have a bad sector. Rather than just throwing those drives out, they disable that bad sector. Now you have two 1TB drives, and eight drives that are a lower capacity. Maybe they test the remaining sectors, and another 2 test fine. So now they have two 1TB drives, two 512GB drives, and six lower capacity. They disable another sector on the remaining 6, and try again. They have three test good, and the rest test fine after disabling another sector.

So by trying to manufacture ten 1TB drives, they actually got two 1TB, two 512GB, three 256GB, and three 128GB drives. They’ll sell the 128GB drives at (or even slightly below) cost, just to recoup some of their expenses. They simply don’t want to write them off as a total loss. The 256GB drives get sold slightly above cost, to make a slight profit. The 512GB’s have more markup,!and the 1TB drives will have a high amount of markup to cover future R&D costs. So the 1TB drives are more expensive, not only because the company wants to cover future R&D, but also because they can’t be made reliably.

But then tech improves, and 1TB drives become easier to make. Reliability improves. Now the company is able to reliably make 9/10 functioning drives, and only 1/10 have a bad sector. But this introduces a new problem for the company... Their market research has found that 512GB drives sell the best, while 1TB drives tend to sit on shelves for a while. So if they just ship 9/10 drives as 1TB, the company will actually lose money as stores end up overstocked.

Instead, they bin the drives according to what will sell the best. They know 512GB’s sell the best, so they take 6 of those perfectly functional 1TB drives, and disable a sector to turn them into 512’s instead. Now they’re selling three 1TB drives, and seven (six of the functional 1TB drives, plus the one from earlier that had a bad sector) 512GB drives. To be clear, those six drives would be perfectly functional as 1TB drives, but they have been artificially limited by the manufacturer to boost sales.

So maybe a generic company buys those 512’s, re-enables the disabled sectors, and resells them as 1TB. It’s a gamble, because 1 of those drives for sure has a bad sector and will fail as soon as the user crosses past the 512GB mark. But the scammer doesn’t care about that, because they’re still making a profit on the remaining six. That’s likely what is happening here, with the seller buying binned drives and re-enabling disabled sectors. But the issue is that the 4TB drives are still likely difficult to make. They’re still in that 2/10 range, not the 9/10 range. So there’s a very good chance that all of the drives will fail before the 4TB mark. It’s not 100% certain… It’s possible you get extremely lucky and actually get a good drive that was artificially binned for sales. But the chances are much much better that you just bought a drive that will fail at 2TB, or 1TB, or even 512GB.