Subject: Re: ccd on ide drives
To: Mike Long <mike.long@analog.com>
From: Michael L. VanLoon -- HeadCandy.com <michaelv@HeadCandy.com>
List: current-users
Date: 01/08/1996 20:53:37
>In fact, IDE controllers have become so dirt-cheap that anyone with
>two IDE drives may want to look into putting the second drive on its
>own controller. The speed increase should more than make up for the
>loss of one free IRQ. YMMV, though.
Yes, I had thought of this also. If you're trying to breath a few
more years life into a couple old IDE drives, this may be a very cheap
performance enhancement.
But, IDE still uses programmed-I/O (busy loops), tying up the
processor for all I/O (unless there have been enhancements for
EIDE/ATAPI that I don't know about). As opposed to SCSI, which allows
the controller to do all the I/O independently of the CPU (at least on
most of the high-end boards supported by NetBSD -- obviously this
doesn't include dumb SCSI boards like the AHA-1522).
So, for new equipment you're still better off getting quality SCSI
components than IDE on multiple controllers. But, for existing IDE on
a small budget, two IDE controllers would probably buy you a bit of
enhanced performance for very little money.
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Michael L. VanLoon michaelv@HeadCandy.com
--< Free your mind and your machine -- NetBSD free un*x >--
NetBSD working ports: 386+PC, Mac 68k, Amiga, HP300, Sun3, Sun4,
DEC PMAX (MIPS), DEC Alpha, PC532
NetBSD ports in progress: VAX, Atari 68k, others...
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