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From: bob@obiwan.pmr.com (Bob Willcox)
Subject: Re: PCI/EISA/ISA performance
To: terry@cs.weber.edu (Terry Lambert)
Date: Tue, 4 Apr 1995 20:04:02 -0500 (CDT)
Cc: matt@lkg.dec.com, vernick@cs.sunysb.edu, freebsd-hackers@FreeBSD.org
In-Reply-To: <9504042255.AA20914@cs.weber.edu> from "Terry Lambert" at Apr 4, 95 04:55:48 pm
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Terry Lambert wrote:
> 
> > > Anyone have any performance results comparing the three types of
> > > buses?  I'm interested in disk I/O performance and/or network
> > > I/O performance using the three buses and DMA.
> > 
> > As a rule of thumb, PCI > EISA > ISA.  
> 
> Whose thumb are you looking at?  8-).
> 
> VLB has a speed limit of 40MHz (typical cards die > 33MHz, though)
> PCI has a speed limit of 33MHz
> ISA has a speed limit of 12MHz
> EISA has a speed limit of bus clock (mine runs at 50MHz)

A recent Buslogic marketing brochure I received claims that their
new EISA controllers (BT-747C & BT-757C) can run up to 66MB/second
using what they call enhanced master burst mode (EMB).  I know
nothing more about it.


-- 
Bob Willcox
bob@obiwan.pmr.com (or obiwan%bob@uunet.uu.net)
Austin, TX