From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 14 Jul 1999 15:13:47 +1000 Message-Id: <199907140513.PAA21479@tango.anu.edu.au> From: Paul Mackerras To: joe_julicher@macktrucks.com CC: linuxppc-dev@lists.linuxppc.org In-reply-to: <3.0.5.32.19990713083902.0080d910@mailhost.bulldog.com> (message from Joe Julicher on Tue, 13 Jul 1999 08:39:02 -0400) Subject: Re: Interesting Beige G3 Storage Stuff Reply-to: Paul.Mackerras@cs.anu.edu.au References: <3.0.5.32.19990713083902.0080d910@mailhost.bulldog.com> Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: Joe Julicher wrote: > IDE HD. The drive gives > 12mb/sec under MacOS. Runs great and I have > used it to record movies at 30fps. Not bad. However, under linux a hdparm > -t /dev/hda gives 1.96mb/s If I do a hdparm -T /dev/hda (to measure cache > performance) it gives 64mb/s. The drive speed seems VERY slow using this > simple benchmark. I would expect much better. There are parameters to > adjust with hdparm, but I haven't messed with them. Do `hdparm -u1 -m16 -p /dev/hda' and you should get around 10MB/s out of it. > The kernel probes the ID's correctly and establishes a sync connection to > each except for the Exabyte tape drive. Later when the kernel probes for > partitions on the 40mb drive, it times out and eventually reboots. I > haven't recorded the information in the big MESH dump that is provided. If > somebody wants that, I will get it. > > I swapped the 40mb with a 250mb Quantum (pull from 7100). This establishes > a sync connection at 10mb/s and runs great. I don't mind ditching the 40mb > but I would like to understand the problem. It seems that the MESH driver > could still use some work OR, I need to recompile a kernel that does not do > sync. transfers. Perhaps I need to blacklist this 40mb drive. Is there a > no-sync blacklist? Not as such. There is a word in the driver with one bit per target which says whether the driver can do sync connections with that target. You could edit the source and recompile to get a kernel where the mesh driver won't do sync with that target. A bit gross, I know. 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. Please check http://lists.linuxppc.org/ ]] [[ and http://www.linuxppc.org/ for useful information before posting. ]]