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Newsgroups: comp.periphs.scsi,comp.os.linux.hardware,comp.os.linux.setup,comp.unix.bsd.freebsd.misc Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!simtel!news.sprintlink.net!in2.uu.net!spcuna!ritz!ritz From: ritz@ritz.mordor.com (Chris Mauritz) Subject: Re: SCSI diskIO Followup-To: comp.periphs.scsi,comp.os.linux.hardware,comp.os.linux.setup,comp.unix.bsd.freebsd.misc References: <417ee7$1kp@trauma.rn.com> <419qu5$r4q@bonnie.tcd-dresden.de> <41fpji$g5a@overload.lbl.gov> <DDs7pM.KLA@ritz.mordor.com> <41g8re$11e@news.cloud9.net> Organization: Mordor International Date: Wed, 23 Aug 1995 23:02:08 GMT X-Newsreader: TIN [UNIX 1.3 950726BETA PL0] Message-ID: <DDsDBK.45q@ritz.mordor.com> Lines: 45 Xref: euryale.cc.adfa.oz.au comp.periphs.scsi:36173 comp.os.linux.hardware:14125 comp.os.linux.setup:18042 comp.unix.bsd.freebsd.misc:5027 Thor Lancelot Simon (tls@cloud9.net) wrote: : In article <DDs7pM.KLA@ritz.mordor.com>, : Chris Mauritz <ritz@ritz.mordor.com> wrote: : >Jin Guojun[ITG] (jin@gracie.lbl.gov) wrote: : >: In article <419qu5$r4q@bonnie.tcd-dresden.de>, : >: J Wunsch <joerg_wunsch@uriah.heep.sax.de> wrote: : >: >news <news@trauma.rn.com> wrote: : >: >>I can't decide on which controller to use. Is the 2940 my only option? : >: >>I have access to an older 2940 (original one) however, I would like to : >: >>know if there is a PCI SCSI host adapter for less money that runs faster : >: >>than the 2940 under FreeBSD, Linux and DOS. : >: > : >: >Well, not faster, but almost at the same speed for very less bucks: : >: >the NCR 52c810. I can easily suck 5 MB/s from a (not too fast) : >: >Seagate disk over it, and 4.8 MB/s (each) when running two disks in : >: >parallel. Ain't this enough for you? : >: >-- : >: : >: I guess you mean 53c810 for 52c810. It is the most less expensive SCSI-2 : >: controller and has the performance reach the SCSI-2 spec. : >: I got 6.6 MBps reading rate on a sigle Seagate Baracuda disk and : >: 8.5 MBps reading rate on double Seagate Baracuda disks on the same controller. : >: It costs $55 now from ACME MICRO-SYSTEM Inc., and about $69 - $79 other places. : >: : > : >So if these things are so fast and so cheap, why not use them instead : >of something like the Buslogic 946C? : : There's not a whole lot of reason. The Buslogic will load the bus : less because it takes its commands out of local memory on the board : instead of by DMA from the host memory across the PCI bus. One could : concievably build an 810 board with local RAM to supply commands but that : would raise the price again. : : You also -- IMHO -- *don't* want to have to debug the NetBSD/FreeBSD : NCR driver if it breaks. It makes extensive use of self-modifying : code. In fact, both the code running on the host CPU and the code : running on the NCR modify the code that runs on the NCR. This is : unpleasant to contemplate. Ewwww...that sounds like a good enough reason for me. Regards, Chris -- Christopher Mauritz | For info on internet access: ritz@mordor.com | finger/mail info@ritz.mordor.com OR Mordor International | http://www.mordor.com/ 201/212/718 internet access | Modem: (201)433-7343,(212)843-3451