Date: Thu, 31 Aug 1995 10:54:28 -0700 (PDT) From: "Rodney W. Grimes" <rgrimes@gndrsh.aac.dev.com> To: gibbs@freefall.FreeBSD.org (Justin T. Gibbs) Cc: pete@kesa26.kesa.com, jbryant@argus.iadfw.net, freebsd-hackers@freebsd.org, pete@rahul.net Subject: Re: 4GB Drives Message-ID: <199508311754.KAA12139@gndrsh.aac.dev.com> In-Reply-To: <199508311611.JAA11646@freefall.FreeBSD.org> from "Justin T. Gibbs" at Aug 31, 95 09:10:54 am
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> > >Now, can you all leave me alone for 30 days so I can go get the stripes > >working, I have small bottleneck that needs fixed :-):-):-) And can > >anyone tell me what the mean and standard deviation of an I/O request to > >an aic7870 is before it hits the drive given 0 scsi bus contention? This > >seems to greatly effect rotation offset on stripe sets when pushed to > >the limits of data coming under the head just after the I/O hits the > >drive. > > Hmm. You'd have to come up with some way to benchmark it since its very > dependant on the sequencer code. I'd be interested to here what your > results were. :) :-). How much control do you have over the controller LED in the sequencer code? Would it be possible to wink it when an I/O CCB comes in from the host, and then double wink it when it goes out the scsi bus? Or am I going to have to find a 128 channel logic analyzer and pull my hair out for a week to try and capture this :-). > So, are you planning on using a 3940W for this type of application? Possibly, prototypes are NCR 825 and aha2940W right now... -- Rod Grimes rgrimes@gndrsh.aac.dev.com Accurate Automation Company Reliable computers for FreeBSD
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