From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 6 Jan 1999 17:01:33 +1100 Message-Id: <199901060601.RAA00588@tango.anu.edu.au> From: Paul Mackerras To: tas@mindspring.com, linuxppc-dev@lists.linuxppc.org In-reply-to: <199901052239.JAA04790@tango.anu.edu.au> (message from Paul Mackerras on Wed, 6 Jan 1999 09:39:13 +1100) Subject: Re: Strange PMAC IDE performance problem Reply-to: Paul.Mackerras@cs.anu.edu.au References: <199901052239.JAA04790@tango.anu.edu.au> Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: I found a register at 0xf3020200 on my powermac G3 which affects the speed of disk transfers. This is at offset 0x200 from the base address of the IDE interface and it is a 32-bit little-endian register. After booting Linux, it has 0x2f8526 in it, but under MacOS it has 0x211025. Putting 0x211025 in (with xmon) increased the speed reported by hdparm -tT /dev/hda from 1.89MB/s to 9.7MB/s ! The disk is a WDC 24300ACL (as reported by hdparm -i /dev/hda). The other hdparm settings were -d1 -u1 -m16. Paul. [[ This message was sent via the linuxppc-dev mailing list. Replies are ]] [[ not forced back to the list, so be sure to Cc linuxppc-dev if your ]] [[ reply is of general interest. To unsubscribe from linuxppc-dev, send ]] [[ the message 'unsubscribe' to linuxppc-dev-request@lists.linuxppc.org ]]