Date: Wed, 22 Mar 1995 21:32:15 +1000 From: Bruce Evans <bde@zeta.org.au> To: freebsd-hackers@freefall.cdrom.com, kuku@gilberto.physik.rwth-aachen.de Subject: Re: Why IDE is bad Message-ID: <199503221132.VAA11806@godzilla.zeta.org.au>
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>Regarding the difference in CPU utilization, could it be - I don't >know the driver internals - that it's the bounce buffer technique >that costs CPU while the SCSI controller uses bus master transfers all >the time? Or were you comparing VLB EIDE vs. SCSI ? This might explain why my Intr time is so much lower than Poul's. I have only 16MB, and don't use option BOUNCE_BUFFERS. The bcopy() for bouncing is done in a call from biodone(). biodone() is called from the interrupt handler, at least for the wd driver. Bruce
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