From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 6 Jan 1999 09:39:13 +1100 Message-Id: <199901052239.JAA04790@tango.anu.edu.au> From: Paul Mackerras To: tas@mindspring.com CC: linuxppc-dev@lists.linuxppc.org In-reply-to: (tas@mindspring.com) Subject: Re: Strange PMAC IDE performance problem Reply-to: Paul.Mackerras@cs.anu.edu.au References: Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: Timothy A. Seufert wrote: > Needless to say, the IDE performance figures are far less than those drives > are capable of! Under MacOS they benchmark much higher (for example, the > 38451 scores 7780 to 9472 KB/s (8819 avg) sustained read on the FWB I have noticed this poor performance myself but it's hard to say what might be the cause - whether it's some bit that needs to be set somewhere in a hardware register, or something about the IDE driver that is causing it to waste time somewhere. One way to start getting some information would be to add some statements to the IDE driver to read the timebase register to get some timing information about how long different parts of the process take. If it is that the hardware is not transferring the bytes very fast, then we need to look for a value in a hardware register which is different between macos and linux. I don't think I will be able to get on to it soon but if someone else wants to have a go that would be great. 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 ]]