*BSD News Article 3616


Return to BSD News archive

Xref: sserve comp.unix.bsd:3661 comp.sys.ibm.pc.hardware:29140
Path: sserve!manuel!munnari.oz.au!mips!mips!sdd.hp.com!wupost!uunet!decwrl!netcomsv!mport!admin!jack
From: jack@admin.mport.COM (Jack Craig)
Newsgroups: comp.unix.bsd,comp.sys.ibm.pc.hardware
Subject: Re: Another Adaptec Question
Message-ID: <866@admin.mport.COM>
Date: 13 Aug 92 19:59:47 GMT
References: <1992Aug12.193421.14456@cs.wisc.edu>
Followup-To: comp.unix.bsd
Organization: Microport Inc., Scotts Valley, CA 95066 US of A
Lines: 32

hollings@cs.wisc.edu (Jeff Hollingsworth) writes:

>There seems to be two versions of the Adaptec 1542A card, one that supports bus
>mastering and one that does not.  I have two questions about this:

not quit, the 1542[a/b] both support(are forced to use) bus mastering.

the 1522 is a pio device(no bus master).

>1.) How much benefit is bus mastering for UNIX (assumming the OS supports it)
A lot! you should talk to neal nelson on this subject, 312-755-1000.
hes doing a paper on it.

>2.) Does either BSDI or 386bsd support bus mastering?
its up to the host adapter and its driver.

>One other question, what exactly do the Adaptec cards do that make them
>more expensive than the Future Domain cards?

i dont beleive the FD card is a bus master. BM takes a cpu on the
card to do the work, that is part of the cost.

jack...
=============================================================================
 Jack Craig      Microport SVR4      408-438-UNIX        uunet!mport.com!jack   
=============================================================================

>-------------------------------------------------------------------------------
>Jeff Hollingsworth					Work: (608) 262-6617
>Internet: hollings@cs.wisc.edu				 FAX: (608) 262-9777
>Home: hollings@warthog.madison.wi.us			Home: (608) 256-4839
>X.400: <pn=Jeff.Hollingsworth;ou=cs;o=uw-madison;prmd=xnren;c=US>