Performance in 486 EISA machines: ISC vs. SCO

[Thomas Solomon]

I don't want to start any flame wars between ISC and SCO supporters
but I need some information about performance of these unices on souped-up
486/33 MHz EISA machines.  I've read quite a bit about pros and cons
of SCO, but the pros and cons discussed deal mainly with features of
the system, rather than shear horsepower.

The Personal Workstation review of ISC and SCO has an intriguing section
in it:  "On the IOBench 2 disk, SCO Unix outperformed Interactive only on
single-tasking reads.  Interactive had an advantage of 25 to 30 percent
on the impotant random read/write test, and of several hundred percent on
sequential writes."  SEVERAL HUNDRED PERCENT!?!??  Is this for real, or
is this a typo?  We are quite interested in sequential writes, because
we will be setting up a partition on our disk for data-taking that will
be wiped clean before every data run (to avoid forcing the head to jump
around).  Can anyone confirm or refute this "several hundred percent" thing?

A few other questions:  do either (or both) of these unices support
486-specific commands (presumably increasing efficiency)?  How about
features specific to the EISA bus, such as bus mastering (very important
for high throughput in disk access) and DMA, and 33 MHz burst mode?  Also,
can either (or both) handle _synchronous_ SCSI transfers to disk?

For the record, we are planning on purchasing an Austin Computer Systems
486/33 MHz EISA machine with an EISA, SCSI, non-caching disk controller
(probably the UltraStor 24F), and a Seagate Elite (ST41600N) SCSI disk
(rated for 3Mbytes/sec internal transfer rate).  We want to get an 
operating system that will take advantage of all the performance of
this machine.  By the way, we are considering putting a DOS partition
on the disk, and using DOS for real-time data-taking, then switch to
unix for the analysis.

Thanks.

					Tom Solomon
					solomon at chaos.utexas.edu