What allocation unit size to select when formatting a hard disk?

Question

I am about to re-format my external hard disk which is formatted as FAT32; I will re-format it into NTFS so that it can accept larger file sizes. The problem now to me is whuch allocation unit size to select?

- Default allocation size?
- 512 bytes?
- 1024 bytes?
- 2048 bytes?
- 4096 bytes?

Answer 1

I usually stick with the default option, and let Windows decide.



A smaller allocation size has less wasted space, but potentially allows for greater fragmentation and a huge file table, and vice versa.

Answer 2

IT depends on the size of the drive, if you have a smaller drive, choose 512 bytes, while it may be possible to have allocation unit size of 512 bytes on a 1 TB drive, it will take up so much space for the allocation table and your OS will have to parse this huge table everytime it searches for a file.

Answer 3

Trying to tweak a large drive to get more storage space is a really bad idea! Unless you're a certified Software Engineer, accept the default, 4096. Saving huge files, like videos, for example, DEMANDS NTFS.



Older settings, in their day were useful, because they were the maximum allowed at the time. But today's huge drives always work best left untouched.



But, do NOT use any 3rd party tools, like Acronis (unnecessary) other than Windows' built-in Partitioning tool, OR a free Utility provided by the hard drive manufacturer. Fdisk, an old DOS utility, can actually damage newer HDDs, for example.



TIP: XHDs are formatted to FAT-32 at the factory for good reason, it's the only one that is usable on Windows, OS X AND Linux, and works best for backing up all your stuff.

Answer 4

Choose 512 bytes ... smaller size, better utilization of space. Its like min space a file occupies. If you choose 4096 bytes, a file which is smaller than that will still occupy 4096. Thus space is wasted.

Answer 5

It's always best to pick the default unless you specifically know what you're doing and have a good reason to change.