difference in allocation unit size - gparted vs MS$ formatting

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difference in allocation unit size - gparted vs MS$ formatting

Post by wpshooter » Tue Nov 13, 2018 3:33 pm

I notice that on some 16gb Sandisk SD cards that I use in my hunting
trail cameras that if I format the SD cards on MS$ computer it makes the
default allocation unit "BLOCK" size 8K but if I format the same cards with
Gparted under Linux Mint the allocation unit size is 32K.

My question is, is there any possibility that this difference in the
allocation unit size would make any difference in the performance
of these cards in/with my trail cameras ?

And the reason I am asking is because on some (but not all) video clips on the
trail cameras, I get displayed environmental temperatures in excess
of 67,000 degrees F. This has been happening during the time that
I was formatting the SD cards with Gparted - I have not yet had
a chance to try the cards after formatting them under MS$.

However, I just formatted them on a MS$ machine and Lordy, it takes
MS$ forever to format these cards when compared to Gparted.


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Re: difference in allocation unit size - gparted vs MS$ formatting

Post by vansloneker » Wed Nov 21, 2018 4:03 am

In the filesystem, files are saved in predefined blocks. Like units on shelves in a storage room. The file takes as many free units as are needed. If e.g. the allocation block size is 32K, and the file size is 40K, the file takes 2 blocks of 32K. One block is used entirely, while the second block is used for 8K of the 32K. The remaining 24K then remain unused. This is called slack.

A general rule is, if you have many small files, a smaller block size is more efficient. If you work with large files, a larger block size could bring a little benefit.

Normally, you don't have to format SD cards. They should be formatted optimal by the factory. Erasing files is enough to free them up. If you have to format a troublesome SD card, it is recommended to use the SD Card Association formatting tool. Since you are also running a Windows system this should be no problem for you.
Unless stated otherwise Mint 18.3-64 XFCE


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Re: difference in allocation unit size - gparted vs MS$ formatting

Post by Mute Ant » Tue Jan 01, 2019 8:13 pm

'...is there any possibility that this difference affects the performance in my cameras...' Yes, so why risk it? Every digital camera I have used offered a 'Format SD' menu item, you should use that.
While you're waiting, read the free novel we sent you. It's a Spanish story about a guy named "manual".

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