Summary: Re: which SCSI card?

From: Lisa Weihl (lweihl@cs.bgsu.edu)
Date: Thu May 14 1998 - 16:19:16 CDT


My original post is at the end. I had asked about choosing between the 2
SCSI card available for a new Ultra 5 were purchasing. I'm VERY new to all
this hardware stuff so I'm just getting my feet wet learning.

Solution... I decided to go with the X6540A ( I forgot a 0 in the orignal
post) since James Ashton told me he was informed by Sun that the card is
really Ultra WIDE SCSI. I tried to verify this with my sales rep but he
said he didn't know. I was also told that my APS drives are probably
SCSI-2 and I assume just have a SCSI-1 case (to be compatible with Macs)
They also SHOULD work on the new server but they'll slow it down.

My next step is to find some other vendors for hard drives. I was just on
Sun's site trying to find out info on a Uni-pack vs Multi-pack without much
success. I don't think our budget can afford Sun drives though. So it
may still be buying from a vendor similar to APS that packages drives in
external cases so we can just chain them up. If anyone has info on decent
vendors with good warranty service. Also if anyone can recommend to me
that Seagate vs Quantum or others works better on a Sun I'd appreciate it.

Many thanks to: Peter Wargo, James Ashton, Andrew Ho, Jeff Wasilko

Here are some of the replies I received.....

4G drives will be SCSI-2, I don't think they ever made 4G SCSI-1. I would
personally go with a dual-channel, and split the drives between channels.
(You'll also need some mini-50 to Cen50 cables, tho you should have one
already.)

My reasoning is this:
#1: two channels *is* better than one.
#2: You could get the fast/wide for future expansion, but it'll still be
choked by the narrow drives.

*************************************************

The key here is finding out what the APS drives are, i want to say they are
scsi 2 drives. If it's a scsi 1 or 2 drive, it will not utilize the speed,
and channel negotiation improvement from the fast-wide, or ultra cards. But
as long as the drive and controllers are all single ended, you just need to
find a cable with the right connectors to get them to work. Just to be
safe, call APS and find out what the drives are and also what format they
are compatible with. My experience with APS and the slim plastic enclosure
is that they will work with either the ultra or fast-wide cards, but the
number of devices you can chain up to the card is very limited ( 3 or 4 at
the most).

However, this will be the least your worries, what will happen with your
machine is that there will be severe disk blocking from slow disks working
with a fast machine and a fast i/o. So in a few weeks time you will have
to explain to your uses and the boss why that the new machine is very slow
whenever is has to write to disk.

I personally would use Ultra scsi cards, and get new drives from APS, or
any local shop. Ultimately the U-W, differential is the best but the combo
is very costly, no likely a school with shell out the cash for it.

*************************************************

I Don't think the X654A can be used to boot the system. It's OEM'd
from someone else (Adaptec, perhaps?).

The X1032A is equivilent to the SunSwift SBus card, and is
designed by Sun. My price book claims that it's UltraSCSI, not
fast/wide.

*************************************************

I assume you mean X6540A. I've just ordered one of these after having
been assured by the salesman that it was a wide adapter, i.e., it's
dual wide UltraSCSI capable of 40MB/sec per channel for a total of
80MB/sec. Please let me know if you have information stating that it's
only narrow---but this would be very surprising.

*************************************************
Original post.......

>X654A dual channel, single-ended Ultra SCSI (SCSI-3 from my research)
>X1032A fast/wide SCSI with 10/100BaseT Enet (Wide SCSI-2??)
>
>We are currently using 4G Quantum drives from APS(APS Q4300) on the
>SparcServer. I'm not sure if those drives are SCSI-1 or SCSI-2. They have
>the Centronics50 connector in the back. They were always purchased because
>they could be used interchangeably between our Macs and Suns.
>
>Is there any major advantage to choosing fast-wide over SCSI-3? I did read
>one sun-mgrs archive that said having 2 controllers will give better
>performance rather than having 1 wide controller with more devices. Most
>of my users login via telnet. And I don't have a huge site maybe 20 users
>are on at once tops.

Lisa-

******************************************************************
Lisa Weihl, System Administrator E-mail: lweihl@cs.bgsu.edu
Department of Computer Science Office: Hayes 225
Bowling Green State University Phone: (419) 372-0116
Bowling Green, Ohio 43403-0214 Fax: (419) 372-8061



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