[SOLVED] True capacity of 512 GB flash drive

rosawoodsii

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I recently bought a PNY 512 GB flash drive and discovered when I plugged it in that it had only 461 GB. A little research revealed that the file system takes up a good portion of the space, but that it should be around 476 GB actual capacity, as there is an expected 7% capacity loss. So I looked around at another brand and found that it, also, had a capacity of 460 GB. 51-52 GB loss--10%-- seems like quite a bit to me, and I'm definitely irritated that manufacturers are basically lying about the capacity. I don't even want to think about the loss for a 1 TB or higher USB.

I have two questions:
  1. Why would the file system take up so much space?
  2. Are there any 512 GB USBs that have 476 GB or above?
 
You will find that the flash drive actually contains 512 GiB of NAND flash memory.

That's 512 x 1024 x 1024 x 1024 bytes, ie 512 GiB (gibibytes).

A small part of that is reserved for the drive's firmware.

The manufacturer sells you a product which purports to have a capacity of 512 x 1000 x 1000 x 1000 bytes, ie 512 GB (gigabytes).

The difference results in about 7% of overprovisioned space.

512GiB / 512GB = 1.07

https://ipv4.google.com/search?q=512GiB+/+512GB

In your case a 512GB drive should have a usable capacity of 476.8 GiB:

https://ipv4.google.com/search?q=512+GB+in+GiB

If Windows is seeing a capacity of 461GiB, then it would appear that the drive's capacity has been misrepresented. However, I would first examine the manufacturer's datasheet to see what is being claimed.
 
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USAFRet

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  1. Please show us a screencap of your Disk Management window
  2. The dichotomy between reported drive size has been a thing for decades.
A "500GB" drive is shown in Windows as 465GB
512GB as 476GB.

And on and on.
There is no "loss".
It is simply a difference in reporting units.
Base 10 vs Base 2.
Human vs computer.
 
You will find that the flash drive actually contains 512 GiB of NAND flash memory.

That's 512 x 1024 x 1024 x 1024 bytes, ie 512 GiB (gibibytes).

A small part of that is reserved for the drive's firmware.

The manufacturer sells you a product which purports to have a capacity of 512 x 1000 x 1000 x 1000 bytes, ie 512 GB (gigabytes).

The difference results in about 7% of overprovisioned space.

512GiB / 512GB = 1.07

https://ipv4.google.com/search?q=512GiB+/+512GB

In your case a 512GB drive should have a usable capacity of 476.8 GiB:

https://ipv4.google.com/search?q=512+GB+in+GiB

If Windows is seeing a capacity of 461GiB, then it would appear that the drive's capacity has been misrepresented. However, I would first examine the manufacturer's datasheet to see what is being claimed.
 
Last edited:

rosawoodsii

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Yes, 7% was my understanding as well.
Can't show a picture of the DM window as I returned the flash drive yesterday, hence my question about whether there are any that truly have the 476 GB they should have.
 

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