disk defragmentation

Do deleted files contribute to fragmentation? I don't know about PCs, but on Mac deleting a file only flags the space as available for a new file. So file is still there until the space is used.

I have an external HD that holds only video clips. Is deleting them enough or should I defrag too for best performance? Thanks.

 

On a Mac, if you secure delete files, the file is gone, not flagged.

Deleting large files will add to the fragmentation of a Windows drive, yes.

 

Most filesystems work that way, the deleting a file marks it as free, not overwriting the data, as that would make deletes and such slower.

 

Is there a one-step way to clean out the drive: delete everything and defrag? I guess I could reformat, but when I changed drive from FAT32 to NTFS, it took a long time.

 

To prevent data from being recovered you need to overwrite the data, format alone generally won't do this.

 

There's nothing confidential about the data. I'm feeding video from a camcorder, through a laptop, to the external drive. When I'm done, I copy the files to my Mac (for editing) and delete them, and then I need the drive to be really clean so it can write new files as fast as possible. No files, no fragmentation, just formatted.

I don't know if first deleting and then defragmenting is the best option, or if there's some sort of one-step reformatting that's thorough but doesn't take a long time.

 

I'm not aware of fragmentation ever slowing down write performance to a drive. I'd say your biggest performance factor is the interface to the PC.