Most modern disk controllers implement track caching and support the preferred interleave of 1:1. An interleave of 6:1 or 3:1 may be more suitable for older single-buffered disk controllers that store data using the MFM encoding method. An inappropriate disk and controller combination formatted with a 1:1 interleave can degrade disk I/O performance by a factor of four or more.
Note that some SCSI and IDE disk controllers have their own cylinder/head/sector translation logic, and will probably ignore any reformat command sent to them.