On Mon, 4 Mar 96 22:33 EST 
 Mike Frisch <mfrisch@saturn.tlug.org> wrote:

 >         Is anybody else running a Sun 4/110 and NetBSD/sparc?  I am just
 > curious to know what the hard disk performance is like?  I just tried the
 > latest kernel which Jason built for us 4/1xx users and am still finding the
 > performance to be a little strange.  Some operations are much faster than
 > SunOS while others are much slower.  (I am running a Micropolis 1558
 > connected to an MT21, so this might have something to do with it, but I have
 > nothing to compare the performance against).
 > 
 >         I _really_ want to run NetBSD/sparc, but this performance is
 > intolerable.  If it takes new hardware, then that's what it'll be.

If you build a kernel from recent sources and add "flags 0x1" to the 
"sw0" line, you will enable DMA (which is disabled by default out of 
paranoia).  The performance increase is substantial.  Andrew Gillham has 
been running on his 4/100 with DMA enabled ever since I worked around a 
hardware bug in the driver about a week ago, and he tells me that he no 
longer sees the occasional data corruption he was seeing.  I'm going to 
give it another week or two before I change the driver to enable DMA by 
default.

Note that test kernel I had up for FTP had a bug in it that kept DMA from 
being enabled on the 4/100..."oops" :-)

--------------------------------------------------------------------------
Jason R. Thorpe                                       thorpej@nas.nasa.gov
NASA Ames Research Center                               Home: 408.866.1912
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