From:	Eric Backus <ericb AT lsid DOT hp DOT com>
Subject:	Re: exception 117 and another point (gnutils)
To:	Christoph Kukulies <kuku AT acds DOT physik DOT rwth-aachen DOT de>
Date:	Mon, 14 Dec 92 10:14:56 PST
Cc:	djgpp AT sun DOT soe DOT clarkson DOT edu
Mailer:	Elm [revision: 66.25]

> --Chris
> 
> Another problem:
> 
> the ported (Eric Backus) Gnu fileutilities (cp, mv etc.), especially
> cp appear to very slow. Copying a 250K file takes 16 seconds and causes
> my hard disk to hum like a bee while the DOS COPY takes only 1 second.
> 
> Why?

I don't think I've seen such poor behavior on my machine.  I do always
have a disk cache program running (pccache), with write-caching
enabled, which would tend to smooth out problems like this.

I believe GNU cp gets its buffer size by calling stat() and using
buf.st_blksize, which probably comes out to be 512 bytes on DOS.
Without a disk cache, this would cause quite a bit of thrashing on the
disk.  No doubt DOS COPY uses a much bigger buffer, and might be able
to do the copy in one read/write operation.

Solution: install a good disk cache program, with write caching
enabled.
--
				Eric Backus
				ericb AT lsid DOT hp DOT com
				(206) 335-2495

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