Personal computing discussed
Moderators: renee, morphine, Steel
ThatStupidCat wrote:What I really hate are the flash drives that advertise a certain size, for example 16GB advertised, but the true capacity might be 2 GB. This leads to massive data loss. You can google this and find tips and tricks to find out if you have the true advertised capacity or a hacked one. Just google "check real flash drive capacity" and you'll get a few hits. Actually I'm looking through the list now. I have some new jump drives I want to check before using them.
meerkt wrote:7.8GB is 2.5% off. I have another unit of the exact same model and that one is 7.75GB.
Chrispy_ wrote:The only thing that might explain a memory stick that is larger than expected is that Kingston harvested defective NAND and it's using a 16GiB NAND die that's full of bad sectors and running heavy on ECC.
Chrispy_ wrote:If you performance-test two different capacity "8GB" SE9 sticks, I wouldn't be surprised to see quite different results between two supposedly identical models.
just brew it! wrote:I did mention in the first post I'm talking about base 10 sizes. I expect to see 8,000,000,000 bytes available.DISKPART reports sizes in binary GB (units of 2^30); storage vendors typically quote capacities in decimal GB (units of 10^9).
Chrispy_ wrote:I would expect that the difference between capacities (if it's not a formatting difference) is different controllers or different firmware allocating more or less spare area for error-correction parity, performance reasons, or something else.
Chrispy_ wrote:Bunnie's SD study was indeed amusing.
meerkt wrote:just brew it! wrote:DISKPART reports sizes in binary GB (units of 2^30); storage vendors typically quote capacities in decimal GB (units of 10^9).
I did mention in the first post I'm talking about base 10 sizes.
meerkt wrote:I expect to see 8,000,000,000 bytes available.
meerkt wrote:All of the above were base-10.
meerkt wrote:What do you mean when you speak of "ratio"?
just brew it! wrote:Chrispy_ wrote:The only thing that might explain a memory stick that is larger than expected is that Kingston harvested defective NAND and it's using a 16GiB NAND die that's full of bad sectors and running heavy on ECC.
I'd be really surprised if they're doing this. Do you have any references that indicate this is common practice in the industry? And has anyone actually seen a drive that is larger than the specified capacity, IN BINARY GB (since the flash chips themselves are sized in binary units)?
Flash memory is really cheap. So cheap, in fact, that it’s too good to be true. In reality, all flash memory is riddled with defects — without exception. The illusion of a contiguous, reliable storage media is crafted through sophisticated error correction and bad block management functions.
In our experience, the quality of the flash chip(s) integrated into memory cards varies widely. It can be anything from high-grade factory-new silicon to material with over 80% bad sectors. Those concerned about e-waste may (or may not) be pleased to know that it’s also common for vendors to use recycled flash chips salvaged from discarded parts. Larger vendors will tend to offer more consistent quality, but even the largest players staunchly reserve the right to mix and match flash chips with different controllers, yet sell the assembly as the same part number — a nightmare if you’re dealing with implementation-specific bugs.