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Bug 83546 - ATA100 doesn't work; only getting ATA33. Missing "ide=ata66"?????
Summary: ATA100 doesn't work; only getting ATA33. Missing "ide=ata66"?????
Alias: None
Product: Red Hat Linux
Classification: Retired
Component: kernel
Version: 7.3
Hardware: i386
OS: Linux
Target Milestone: ---
Assignee: Arjan van de Ven
QA Contact: Brian Brock
: 83560 (view as bug list)
Depends On:
TreeView+ depends on / blocked
Reported: 2003-02-05 15:41 UTC by Aaron Freed
Modified: 2007-04-18 16:50 UTC (History)
0 users

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2004-09-30 15:40:29 UTC

Attachments (Terms of Use)

Description Aaron Freed 2003-02-05 15:41:50 UTC
Description of problem:
Unable to get true ATA100 performance from RedHat 7.3.  No matter what I do with
hdparm, I still get about 22 MB/sec transfer rate from the ATA100 IDE drive,
which is about what I get from my other two systems, both of which are only

Version-Release number of selected component (if applicable):

How reproducible:
Guaranteed.  Cannot get any better performance! ;-<

Steps to Reproduce:
1.Install RedHat 7.3
3.Run hdparm -t /dev/hda1 as root
4.See poor result.
5.Be disappointed.

I seem to recall that there was a parameter I could pass to the kernel during
the boot process, by appending it to the end of the appropriate line in
/etc/grub.conf like this: (added parameter highlighted by "^^^^^^^^^"

    title Red Hat Linux (2.4.18-24.7.xbigmem)
        root (hd0,0)
        kernel /vmlinuz-2.4.18-24.7.xbigmem ro root=/dev/hda2 hdc=ide-scsi ide=ata66
        initrd /initrd-2.4.18-24.7.xbigmem.img

Actual results:

Have not tried it, yet.  Don't want to trash the central server with an
incorrect parameter!

Expected results:
data transfer rate of > 40 MB/s, as reported by hdparm -t /dev/hda

Additional info:
I know I reported this once before and Dave Ledford (I think?) kindly sent me
the instructions regarding a parameter similar to the above that fixed all my
problems and brought about World Peace (almost), but I cannot find that e-mail
or the original bug.  I'm really sorry to bother you with this again, and I
really do appreciate it!

Comment 1 Arjan van de Ven 2003-02-05 15:58:55 UTC
the actual parameter is
for the first "cable", ide1=ata66 for the second cable etc etc.
Only do this if you have the 80 ribbon cable! 

Comment 2 Arjan van de Ven 2003-02-05 16:55:24 UTC
*** Bug 83560 has been marked as a duplicate of this bug. ***

Comment 3 Aaron Freed 2003-02-05 19:05:29 UTC
Thanks!  That seems to have sped things up a bit!  Can I get even more bang with
"ide=ata100", or does "ide=ata66" already include that?

Thanks again, Arjan!

Comment 4 Arjan van de Ven 2003-02-05 21:22:02 UTC
ide0=ata66 already includes that. the only thing that matters is 40 vs 80 ribbon
cable; something that not always can be autodetected.

Comment 5 Bugzilla owner 2004-09-30 15:40:29 UTC
Thanks for the bug report. However, Red Hat no longer maintains this version of
the product. Please upgrade to the latest version and open a new bug if the problem

The Fedora Legacy project ( maintains some older releases, 
and if you believe this bug is interesting to them, please report the problem in
the bug tracker at:

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