Re: Adaptec-2920 eats too much cpu time when reading from the CD-ROM

From: Alan Cox (alan@lxorguk.ukuu.org.uk)
Date: Thu Dec 06 2001 - 09:11:56 EST

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> There is one interesting thing about it: when I write a CD, I write at 12x
> - that means 1800Kb/s, which is comparable with the reading speed of 2400Kb/s.
> But when writing, the system CPU usage is about 30%.

When you write the scsi layer keeps getting to the point where there are
no commands to issue. When you read its always there waiting for the drive.

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