08-27-2017 10:56 AM
I just bought a 128 GB USB flash drive. I know that due to the 1024-bytes convention it doesn't show 128 GB in Windows. However, I do understand that 128 GB means 128,000,000,000 bytes. That is even written in the fine print on the backside of the blister pack. And 128,000,000,000 bytes translates for me (/1024^3) to 119 GB. Now, my stick only shows 114 GB (or 123,000,000,000 bytes). So there are definitely 5 GB missing from what is advertized!
So, where did this space go? Does SanDisk use 5 GB for firmware and wear leveling? Why do other manufacturers (e.g. Lexar) deliver what is advertized (i.e. 128 GB appear with 119 GB in Windows)?
Thanks for answering,
08-28-2017 07:48 AM - edited 08-28-2017 07:48 AM
this the explination on the sandisk knowledebase. i underlined the specific explination for the capacity difference. This is common among all flash memory manufacturers.
Why is the capacity of my device (as reported by many operating systems) different than the capacity that is listed on its label?
All SanDisk products include the total capacity, at an unformatted level, that is stated on the product packaging. For example, a 128GB SanDisk USB flash drive has a total capacity of 128,000,000,000 bytes at the unformatted level (where 1GB=1,000,000,000 bytes).
Definitions of a Megabyte:
Note: Some capacity is used for formatting and other functions and thus not available for data storage.
A portion of the total capacity is used to store certain functions including optimizations of the memory that support performance and endurance and therefore is not available for user storage. This is disclosed on our packaging and marketing materials when you see the statement "Actual user storage less."
As a leader in flash storage technology, SanDisk offers multiple products at different speeds and capacities to address a variety of consumer needs. To provide the optimum product for you, we're continuously improving and updating our technology, products, firmware, and design. Continual improvements and updates are made to our product (both new products and existing product lines) and can include changes to the basic file structure, formatting and other functions. These optimizations may result in variances as to the amount of memory space that is available for user storage, but are essential to performance and endurance of the products.
09-02-2017 11:07 AM
Maybe this helps:
Important files = Backed up files