Usb drive format ntfs allocation unit size

The other reason the real size of a file and the amount of space it takes up on a disk are different has to do with the allocation units size. This is because computer memory and storage are measured in binary units, not decimal, but thatвЂ™s not strictly related to allocation unit size. ItвЂ™s because of the rather silly fact that everyone defines a megabyte as 1024 kilobytes, except for hard drive makers who round it to 1000.

The main reason for this has nothing to do with allocation unit sizes. The formatted space of a hard drive is different from the total raw space advertised on the packaging. What Effect Does Allocation Unit Size Have on Drive Space? The problem here is that open units can be scattered all across the drive as files are written and deleted over time. ThatвЂ™s because any files that are larger than the allocation unit will be written to multiple units. Having a very small allocation size can also lead to extreme fragmentation. Again, on mechanical drives this is a significant problem because it physically has to move the read/write heads of the hard drive to the location of the allocation unit you want it to access. That is, how long it takes to look up the location of the file in the file allocation table and then to access the correct allocation units. This reduces the вЂњseek timeвЂќ of the drive. So when your computer has to look up the physical location of your data, the address book is much thinner. This makes sense because your вЂњplotsвЂќ of drive real estate are larger. Basically, the bigger you make the allocation unit size, the fewer the total number of allocation units. What Effect Does Allocation Unit Size Have on Performance?ДЄllocation unit size does have an effect on drive performance.

So the default allocation size that youвЂ™re offered when formatting a drive is a general purpose size that should work for most people, most of the time. Fragmentation is also in part a function of allocation size. Then we have the issue of solid state drives, which donвЂ™t suffer from performance loss when file fragmentation happens.

Usb drive format ntfs allocation unit size