evans@ditsyda.oz (Bruce Evans) (09/18/89)
In article <23940@louie.udel.EDU> SQ79%liverpool.ac.uk@nsfnet-relay.ac.uk (Mark Powell) writes: >Does anybody know anything about optimum interleave factors >for hard disks under MINIX. Recently I changed the interleave >factor on my Western Digital Filecard (21meg) (which >incidentally runs under MINIX with no trouble) from 4 to 10. >This resulted in a near 3 times speed increase under DOS, but >showed minimal difference under MINIX. Is it possible to >have separate partitions with a different interleave factor? >If so where can I get the necessary software to achieve this? The DOS shareware program IAU.EXE will determine the best interleave (for DOS :() and change the interleave without reformatting or (with luck) losing your data. It works with the raw disk so doesn't care about partitions, and each track can have a different interleave. Surely not an interleave of 10? That gives 17/10 times the slowest speed so can't be 3 times faster. I don't like interleaves, they inherently cut performance by a factor, unless the software is clever enough to determine and undo the effects of the interleave. I have modified the Minix floppy driver to keep up with the standard interleave of 1 (only works on a 386 so far). Same for the AT hard disk driver with my chosen interleave of 2. FS needed mods too. My PC hard disk has interleave 3, best for DOS but poor for Minix even with the modifications. -- Bruce Evans evans@ditsyda.oz.au