Apparently, 256GB = 233 GB!

My new Sandisk Ultra USB 3.0 thumb drive says 256GB on the back but in Computer Management/Disk Management, it has one 233.25 GB partition that cannot be extended.

The thumb drive’s Properties are as follows:

Used space: 97.0 MB
Free Space: 250,346,389,504 bytes (233 GB)

So a 256GB thumb drive only has 250,346,389,504 bytes which really equals 233 GB…say what???

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A common question . . .

The answer

Not really.

San Disk state their definition of a GB is 1,000,000,000 Bytes.

256,000,000,000 Bytes by that logic should be the size of the drive. Using the binary figures for KB, MB and GB means we should have ~238.5 GB under that definition so San Disk are still ~5.5GB short.

How many bytes are manufactured and how many Windows uses are two different perspectives.

If you have 1000 bytes and Windows’ blocksize format is 900 bytes then Windows will show 900 bytes used and will not be able to use the other 100 bytes.

Pretty sure NTFS block size is 4KB which divides into 256,000,000,000 Bytes without remainder.

For exFAT block size is 128KB for which the story is the same.

Even if they didn’t I wouldn’t expect it to account for such a large discrepancy…

You do realize that 256,000,000,000 Bytes is not 256 GB right? You’re confusing digital numbers with hexadecimal numbers. 256 x 4 = 1024 not 1000.

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Brother please do read what has been written.

SanDisk state that for marketing purposes they consider a GB to be 1,000,000,000 Bytes.

That means their 256GB memory stick should be 256,000,000,000 Bytes according to their own standards.

Now if they were going by the proper definition of a GB we should actually have 262,144,000,000 Bytes but that’s moot because of the above.

As was already stated if SanDisk are defining a GB as 1 billion Bytes we should have 256 billion Bytes which divided by 1024 gives us 250GB so, once again as already noted before would give us 238GB so as I already said SanDisk are short a few real GB by their own standards.

As to your block size point on the TB scale we’re usually talking about losing a few MB for modern formats to lose GB on 256GB is far too large to be accounted for with block size. Furthermore as 256 billion bytes (which I reiterate the drive should be by SanDisk’s own standards) divides by 4KB without remainder (as in 4096 bytes) theoretically we don’t lose listed capacity to alignment issues. We simply have less capacity to use if we’re storing lots of files smaller than the block size.

Also what on earth are you talking about Hexadecimal numbers for? Hex hasn’t come up once and is simply a different base. We’re talking about the values that can be represented with by a 1 in a given position in a binary number (1,2,8,16,32,64,128,256,512,1024 etc) none of these numbers are “Hexadecimal”.

Have you ever heard of the File Allocation Table? Or it’s backup? How about Recovery Bytes, heard of them? They are part of a drive that take up space that the user can’t allocate to their files but count as bytes manufactured.

Ever heard of a file allocation table 5GB in size for an empty drive?

No? Me either…

Stop throwing ■■■■ at the wall to see what sticks. Even unformatted in cgdisk these drives are undersized. Unformatted, which means entirely empty with no space taken up by file allocation or partition tables and no recovery partition.

Unless you’ve got something with a shred of viability to explain the 5GB don’t bother replying.

Every heard of Recovery Bytes being allocated when formatting?

No? Me either…

Unless you’ve got something with a shred of viability other than a XXXX option don’t bother replying.

BTW What brand drive did you get when you returned the one you’re complaining about?

What are you even on about with recovery bytes?

If you’re talking about the miniscule fraction of a drive dedicated to error correction and data integrity we’re talking about between .1% and .5% of the capacity of the drive and dude that doesn’t even come close to 5GB.

Beyond that, when you’re being sold a storage device with a given storage capacity it’s not unreasonable to expect that the listed size will be usable storage.

It’s easy enough to respond to every query like this with the simple 1024MB Vs 1000MB even though that doesn’t tell the whole story and it doesn’t actually help anyone.

Obviously, the drive is a counterfeit.