From owner-freebsd-hackers Mon Jan 2 19:30:19 1995 Return-Path: hackers-owner Received: (from root@localhost) by freefall.cdrom.com (8.6.9/8.6.6) id TAA09342 for hackers-outgoing; Mon, 2 Jan 1995 19:30:19 -0800 Received: from godzilla.zeta.org.au (godzilla.zeta.org.au [203.2.228.34]) by freefall.cdrom.com (8.6.9/8.6.6) with ESMTP id TAA09336 for ; Mon, 2 Jan 1995 19:30:12 -0800 Received: (from bde@localhost) by godzilla.zeta.org.au (8.6.9/8.6.9) id OAA25453; Tue, 3 Jan 1995 14:26:05 +1100 Date: Tue, 3 Jan 1995 14:26:05 +1100 From: Bruce Evans Message-Id: <199501030326.OAA25453@godzilla.zeta.org.au> To: hackers@freebsd.org, terry@uivlsi.csl.uiuc.edu Subject: Re: Emulex MD21 question Sender: hackers-owner@freebsd.org Precedence: bulk > By any chance is anyone here familiar with the Emulex MD21 ESDI->SCSI >bridge? I'm trying to use one with a 10MHz ESDI drive and a 15MHz ESDI drive. >It does work, but the transfer rate to the 15MHz drive is only about 650KB/s. >I measured the transfer rate by both dd and CORETEST (DOS benchmark). It is >as if the MD21 formats 15MHz drives with a 2:1 interleave. Is this >a limitation of the MD21? Thanks for your time. Some controllers can't keep up with 15MHz unless the drive is formatted with 2:1 interleave. I had this problem with a WD1007V-SE/1 controller. I enjoyed trashing my 10MHz and 15MHz ESDI drives (original cost US$2250) and replacing them with a US$300 IDE drive to get twice the performance. Bruce