Re: [cobalt-users] Qube3 - Speed Increase

[Parker Morse <morse@xxxxxxxxxxx>]

On Sunday, September 22, 2002, at 05:30  AM, Sonny Taite wrote:
> On 9/22/02 7:41 PM, "Sonny Taite" <sonny@xxxxxxxxx> wrote:
> > THE USUAL WARNINGS :: USE AT YOUR OWN RISK - NO RESPONSIBILITY TAKEN BY 
> > ME
> > OR ASSOCIATES OF ME FOR LOSS OF INFORMATION.

> /sbin/hdparm -X66 -d1 -m16 -c3 /dev/hda

I'm intrigued, but I wanted to look before I leapt. So I ran

$ man hdparm

and found the following warnings; for -X66:
              mode2 transfers (you'll need to prepare the chipset
              for UltraDMA beforehand).  Apart from that, use  of
              this flag is seldom necessary since most/all modern
              IDE drives default to their  fastest  PIO  transfer
              mode  at  power-on.  Fiddling with this can be both
              needless and risky.  On drives which support alter-
              nate  transfer  modes, -X can be used to switch the
              mode of the drive  only.   Prior  to  changing  the
              transfer mode, the IDE interface should be jumpered
              or programmed (see -p flag) for the new  mode  set-
              ting  to  prevent  loss  and/or corruption of data.
              Use this with extreme caution!  For the  PIO  (Pro-

and for -m16:
              output).   Some  drives  claim  to support multiple
              mode, but lose data at some settings.   Under  rare
              circumstances,  such failures can result in massive
              filesystem corruption.

However, it has clearly worked for Sonny.

Bearing in mind that many of us - particularly Qube users - ARE appliance 
operators and thirsty for enlightenment, can someone expand on why this 
might (or might not) be a worthwhile risk to take? I can easily believe 
that Sun would ship the Qube without this sort of optimization, but I have 
a harder time believing that I know the hardware better than they do. :-)

Thanks,

pjm