Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!ssbell!mcmi!dsndata!wayne From: wayne@dsndata.uucp (Wayne Schlitt) Newsgroups: comp.sys.ibm.pc Subject: Re: Speeding up disk accesses - Food for thought. Message-ID: Date: 16 Jan 90 01:33:06 GMT References: <361@marvin.moncam.co.uk> Sender: wayne@dsndata.UUCP Organization: Design Data Lines: 24 In-reply-to: emmo@moncam.co.uk's message of 14 Jan 90 16:16:23 GMT In article <361@marvin.moncam.co.uk> emmo@moncam.co.uk (Dave Emmerson) writes: > [ ... ] > > The object of this is simply to keep the most often read tracks closest > to track 0, this should reduce the amount of stepping needed to access > any particular file more often than not. Even if the speed gain is > negligable, the saving in wear and tear on the stepper motor is worth > this small effort. actually on the mainframe systems i used to administer, we tried to keep the most used/important files in the center (middle track) of the disk. that keeps the max seek down to 1/2 of the disc, and the average seek to 1/4 of the disc. if you put the important stuff on either end you will have a max seek of the entire disc and an average of 1/2. this, of course, assumes that your disc is basically full, or with the files distributed evenly across the disk. i also dont remember were exactly the fat table is on msdos and i dont know how often msdos read/writes it. i suppose if the fat table is at the front of the disk and you dont have any disk caching, then yes, the front of the disc is where you want to put important stuff. -wayne