512GB SSD only ~475 GB actual?

[marcplante]

I'm upgrading my wife's Samsung ATIV9 notebook with a new M.2 SSD. I bought a transcend drive and plugged it into a USB3 adapter to attach to her notebook to set up a clone, and I was surprised when Acronis found the drive to be approximately 475 GB (Not sure of the exact amount, but a good chunk less than the 512 labeled.

That seems like ~5% loss. Is that typical with SSDs? I don't recall that much loss on my traditional 500GB HD

Also the disk has not been initialized yet, so would that change when it is formatted and partitioned?

My wife isn't enough of a power user that she'll be wanting for drive space, but I believe i recall there being lawsuits about drive space indications versus actual size in the past.

Just curious,

Marc

 

[sm625]

1 kibibyte = 1024 bytes.
1 mebibyte = 1024*1024 = 1048576
1 gibibyte = 1024*1024*1024 = 1,073,741,824 bytes
512 GB = 1,073,741,824 * 512 = 549,755,813,888

And what happens if you take 512000000000 / 549,755,813,888? You get the number 0.9313

And when you take 512 and multiply that by 0.9313? You get 476.8

The discrepancy stems from the fact that a KiB is 1024 bytes not 1000 bytes. Once you multiply that 2.4% error several times, you get a pretty significant discrepancy, as you can see.

 

[marcplante]

Aha. ..remember 1024. Just like goofs new tablet pricing