Re: How to change DVD-ROM speed?

From: Jens Axboe (
Date: Wed Jun 27 2001 - 12:41:27 EST

On Wed, Jun 27 2001, Jeffrey W. Baker wrote:
> I am trying to change the spin rate of my IDE DVD-ROM drive. My system is
> an Apple PowerBook G4, and I am using kernel 2.4. I want the drive to
> spin at 1X when I watch movies. Currently, it spins at its highest speed,
> which is very loud and a large power load.
> /proc/sys/dev/cdrom/info indicates that the speed of the drive can be
> changed. I use hdparm -E 1 /dev/dvd to attempt to set the speed, and it
> reports success. However, the drive continues to spin at its highest
> speed.

Linux still uses the old-style SET_SPEED command, which is probably not
supported correctly by your newer drive. Just checking, I see latest Mt
Fuji only lists it for CD-RW. For DVD, we're supposed to do
SET_STREAMING to specify such requirements.

Feel free to implement it :-)

Jens Axboe

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