Subject: Re: wd(4) questions
To: Manuel Bouyer <bouyer@antioche.eu.org>
From: Dieter <netbsd@sopwith.solgatos.com>
List: netbsd-help
Date: 08/21/2005 15:56:38
> > I was expecting write to be slower than read, but not this much slower.
> > Is this typical, or do I have something wierd going on?
> 
> Maybe you have the write cache turned off ?

Of course!

Since it isn't running production yet, I turned the disk's
write cache back on, and the write speed increased from
6.5 MB/s to 7.7 MB/s.  Still a lot slower than I would expect.

I looked at a review of the drive, and they got 69.8 MB/s
at the beginning of the disk and 39.9 MB/s at the end
(reading).  I get about 37 MB/s regardless of where on
the disk I'm reading.  Their disk is the 400 GB (3 platters),
mine are the 250 GB (2 platters).  Seagate's pdf file says
"Sustained Transfer Rate OD (Mbytes/sec)" is 65 for both models.
(doesn't specify read or write. or explain what "OD" means)