From: Kai Shing O'Yang (oyang@cs.monash.edu.au)
Date: 06/30/93 

From: oyang@cs.monash.edu.au (Kai Shing O'Yang)
Subject: 2 SCSI cards in the same Linux box?
Date: Wed, 30 Jun 1993 21:12:46 GMT

Hi,
My proposed setup is to have a Adaptec 1742 EISA SCSI card connected to 2
FAST-SCSI II drives while having the 1542b connected to slower devices
like CD-ROM and tape. Would I have any advantage on this config than
hooking all the devices with the 1742?

I tend to believe that slower devices will hold the SCSI bus for longer
times and will affect performance on the faster hard disks (if the hard
disks are on the same scsi bus as the tape, cdrom, etc). But since
EISA can chew up the SCSI thruput quite easily, simultaneously access on
both SCSI buses shouldn't deter the cpu performance. Am I correct?

However, since I'm putting in an ISA 1542b into the system, the Linux kernel
has to do double buffering. Would this drag down overall performance even
during disk only access?

BTW, the cpu is 486dx2-66, and 20MB ram, if that matters.

Thanks in advance,
Kai