On Nov 7, 2003, at 7:46 PM, Joshua Coombs wrote:

> So, the net result of this is a slower machine with a faster harddrive
> looks poor in a cooked test with no scientific basis.  Anyone have any
> tweaking suggestions to help tune up the 68030 software wise?

So, the SE/30's SCSI does not support DMA.  The CPU is involved in 
pushing the data out the SCSI bus (there is a FIFO between the CPU and 
the SCSI chip to help with this, but the CPU is basically the DMA 
engine :-)

In contrast, the PC system you tested has a disk controller that can do 
DMA on its own.  So, naturally, the PC system is going to be faster 
(hey, it has a faster processor, too :-)

Anyway, I suspect there's very little you can do to make disk I/O much 
faster on an SE/30.

         -- Jason R. Thorpe <thorpej@wasabisystems.com>