Re: [Bug 12309] Large I/O operations result in slow performanceand high iowait times

[Henrique de Moraes Holschuh]

On Tue, 30 Mar 2010, Thomas Pilarski wrote:
> This problem is enormous increased, while the ultra bay disc is acceded
> with udma2 instead of udma6 (caused by another bug), 

There is a thinkpad BIOS bug that could cause that: it will not signal a
80-wire cable when you hot-add an HD on a PATA ultrabay.  Exists at least on
all T4x, including the T43.

The fix is to whitelist these thinkpads for high-speed UDMA even on 40-wire
cables.  The workaround is to add a kernel command line parameter (I forget
which).

Does that match your udma2 instead of udma6 problem?

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh
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