Hello,

I just tested four different SCSI controllers on my AlphaPC164.
They were all tested in the same slot, and with the same cable and
drive.  A single filesystem was created, and I ran bonnie with the
default 100MB file.  No special options were enabled or disabled for
these controllers. (so tagged queueing was up to the driver, etc)
The system:
	AlphaPC164 with 500Mhz 21164A
	64MB RAM (128bit mode)
	S3 Trio64 video card
	SMC EtherPower PCI 
	NetBSD -current from December 2

The controllers: (and cost for Retail Box @buy.com)
	Adaptec 2940UW (Ultra/Wide, ahc driver)			$259.95
	Advansys ASB3940UW (Ultra/Wide, adw driver)		$102.95
	Advansys ASB3940UA (Ultra, adv driver)			$ 51.95
	Promise SYM53C810A based (Fast SCSI, ncr driver)	$ 51.00

The drive:
	Seagate Hawk 2GB, Fast SCSI

The results:
              -------Sequential Output-------- ---Sequential Input-- --Random--
              -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU  /sec %CPU
adv2gb    100  2251 15.1  2238  4.0  1294  2.7  3957 25.5  3987  5.0  70.9  1.6
adw2gb    100  3844 25.8  3711  6.8  1463  3.0  3959 25.3  3989  4.9  69.9  1.5
ahc2gb    100  2253 15.7  2234  4.0  1293  2.4  3957 26.2  3987  4.6  70.0  1.3
ncr2gb    100  2254 15.0  2237  4.5  1293  3.1  3955 24.8  3987  5.6  70.3  1.3
ahctag    100  3841 25.7  3718  6.8  1462  2.7  3966 25.5  3987  4.6  71.4  1.6
^^^^^^ with options AHC_TAGENABLE

So, tagged queuing makes a big difference for output!  Also, the controllers
without tag support performed almost identical with the ncr driver using
a bit more cpu. (except in the Per Char output)

Note that I don't have an Ultra/Wide drive to test with, so I can't really
project how the Adaptec and Advansys cards will compare at UW speeds.

For my $$$ the Advansys seems to be an excellent board, and (at least with
my fast scsi drive) performs just as good as the Adaptec, at 40% of the
cost!

I hope to hook up a 5 x 1.7GB Fast SCSI RAIDframe array soon, and compare
them again.  Hopefully this will point out some differences in hardware CCB
support, etc.  For that I will probably use a 500MB file size.

-Andrew
-- 
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Andrew Gillham                            | This space left blank
gillham@whirlpool.com                     | inadvertently.
I speak for myself, not for my employer.  | Contact the publisher.