On Apr 24,  9:29pm, "Stephen J. Roznowski" wrote:
> > From: osymh@gemini.oscs.montana.edu (Michael L. Hitch)
...
> >  Also, the equivalent of what Sysinfo does would probably be:
> > 	dd if=/dev/rsd0c of=/dev/null bs=1024k count=10
> 
> Just tried that -- got ~2.5Mbytes/sec now. I'm running with an 8K/1K
> filesystem. Is a 16k one that much faster?

  Under typical system use, a 16K blocksize probably isn't going to be
noticably faster.  Any speed increase would probaby only show up when
using large files with big transfer sizes.  I think I may have seen a
slight speedup of a kernel compile, but it's been so long since I tested
that, I can't be sure of it.

  I also suspect that tweaking the file system parameters probably
isn't going to make a whole lot of difference in the overall performance.
A lot of the I/O is likely to be small transfers (512, 1K, 4K, or 8K),
and if there is more than one process doing I/O, the I/O will be scattered
over the disk.  I see much more improvement in I/O performance by using
a higher performance disk.  NetBSD runs much better on my Maxtor MXT-540SL
than it does on my Maxtor 7345SY.

Michael

-- 
Michael L. Hitch			INTERNET:  osymh@montana.edu
Computer Consultant
Office of Systems and Computing Services
Montana State University	Bozeman, MT	USA