Article View: comp.sys.ibm.pc.misc
Article #10920Re: Disk seek optimisation
From: Tim Iverson
Date: Fri, 07 Jun 1991 17:13
Date: Fri, 07 Jun 1991 17:13
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In article <1991Jun07.024728.29844@xstor.com> iverson@xstor.com (Tim Iverson) writes: >you can improve by leaps and bounds over FIFO by using an algorythm that >reduces seek distances and/or latency time - latency is very hard >(impossible?) to reduce by scheduling and remain efficient. Argghh. I forgot about SCSI's modify data pointer: 0 latency by telling the host adapter what block is coming (perhaps different from the initially requested block) and then transferring the block under the head *now*. Above, I was referring to reducing latency via head scheduling - certainly possible, but probably prohibitively expensive in terms of calculation time. - Tim Iverson iverson@xstor.com -/- uunet!xstor!iverson
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!xstor!iverson From: iverson@xstor.com (Tim Iverson) Newsgroups: comp.sys.ibm.pc.misc Subject: Re: Disk seek optimisation Message-ID: <1991Jun07.171325.2963@xstor.com> Date: 7 Jun 91 17:13:25 GMT References: <1991Jun5.111750.951@csc.canterbury.ac.nz> <1991Jun07.024728.29844@xstor.com> Reply-To: iverson@xstor.com Organization: Storage Dimensions, Inc. Lines: 14