Subject: real speed of ESP100A ?
To: None <port-sparc@netbsd.org>
From: Manuel Bouyer <bouyer@antioche.lip6.fr>
List: port-sparc
Date: 04/27/2001 23:48:18
Hi folks,
I've an interesting question: can a ESP100A on a SS20, running at 40Mhz,
really do 10MB/s on the SCSI bus ?
From esp_sbus.c:
	        /* Min clocks/byte is 5 */
		sc->sc_minsync = ncr53c9x_cpb2stp(sc, 5);
So 40/8 -> 8Mhz, so 8MB/s
Before merge of the fas support, my disk probed as (on thorpej_scsipi branch):
sd0: Sync (124.0ns offset 15), 8-bit (8.064MB/s) transfers, tagged queueing

Now it probes at 10MB/s; and I suspect some of the problems with the
esp driver comes from that (disk and controller arn't at the same speed).

--
Manuel Bouyer <bouyer@antioche.eu.org>
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