Date: Wed, 11 Nov 1998 18:44:59 +0100 From: Martin Cracauer <cracauer@cons.org> To: =?iso-8859-1?Q?S=F8ren_Schmidt?= <sos@freebsd.dk>, Martin Cracauer <cracauer@cons.org> Cc: john@isi.co.jp, grog@lemis.com, hackers@FreeBSD.ORG, mike@smith.net.au, ticso@cicely.de Subject: Re: SCSI vs. DMA33.. Message-ID: <19981111184459.A10448@cons.org> In-Reply-To: =?iso-8859-1?Q?=3C199811111730=2ESAA01133=40freebsd=2Edk=3E=3B_from_S=F8?= =?iso-8859-1?Q?ren_Schmidt_on_Wed=2C_Nov_11=2C_1998_at_06:30:36PM_%2B0100?= References: <19981111164136.A29513@cons.org> <199811111730.SAA01133@freebsd.dk>
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In <199811111730.SAA01133@freebsd.dk>, Søren Schmidt wrote: > It seems Martin Cracauer wrote: [... about two promise cards for IDE striping] > > Guess what: While I can use the two PCI cards simultaneously, I can't > > do so for the two channels on each card, although they are even two > > completely independent chips on each Promize card. Since I don't have > > enough PCI slots for 4 cards (and these things cost money) and my > > motherboard doesn't do UDMA, I'm stuck with performance like my SCSI > > CCD with two Atlas drives. That isn't too bad, but not what I hoped > > for. > > > > Maybe it's a problem with our Promise driver? I already contacted John > > Dyson, but no response yet. Anyone else can think of a solution? > > Hmm, it works for me, I have this little tweak to wd.c though, > without it the promise sometimes blows up... What means "work"? I get a functional ccd filessystem over 4 drives/4channels/2cards, so far so good. But while the throughput is raised when striping over different cards, it isn't when striping over two channels on the same card. Or in other words, the maximum thoughput for a (2x) 4-drive, 4-channel, 2-card ccd is the same as for a (2x) 2-drive, 2-channel, 2-card array, while (1x) 2-drive, 2-channel, 1-card is excatly the same as for (1x) 1-drive, 1-channel, 1-card. Hence my impression I can't use the two channels on one card simultaneously. Is this really different for you? Do you have the promise BIOS prom installed? Thanks for the fix, BTW, does this fix the IDE timeouts I see when striping over 4 drives? Martin -- %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Martin Cracauer <cracauer@cons.org> http://www.cons.org/cracauer Tel.: (private) +4940 5221829 Fax.: (private) +4940 5228536 Paper: (private) Waldstrasse 200, 22846 Norderstedt, Germany To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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