SCSI speed with IBM DGVS09U (8 GB) hard drive, Linux

[Steve Swanson]

Please stop sending e-mail to dgregory at budco.com  He no longer works for
Budco.

At 01:53 PM 1/6/99 -0500, Ricky Beam wrote:
>Letting the chips fall where they may, I quote Albert Max Lai:
>>On Sun, 3 Jan 1999, Andy Kennedy wrote:
>>> Jochen,
>>> 	I have a similar problem.  From what I understand from information
>>> that has been given from people on the list, you cannot have one disc
>>> running at 40 and another running at 10????  I have 4 UW's and 1 N and I
>>> have to run all of the discs at 10.
>>
>>I thought that the ability to run discs at different speeds was a selling
>>point for Adaptec (or is that only on U2W adapers?). I have an aic-7895
>>onboard a Tyan 1836DLUAN with a DGVS09U that runs at 40 MB/sec, a narrow
>>Quantum viking running at 20 MB/sec, and a Toshiba XM-3702TA CD-ROM
>>running at 4.4 MB/sec. So, at least for me, it seems that you can have a
>>variety of speeds on a single bus (all are connected to bus 0).
>
>U2 SCSI is LVD -- Low Voltage Differential.  You generally cannot mix LVD
>and non-LVD devices on the same physical cable without causing problems.
>That does not say it cannot be done at all.
>
>As long as all the devices are SE (Singal Ended), then you can put the
>slowest crap SCSI-1 device on the bus with the most modern high speed
>SCSI-3 device.  (That was part of the design spec from the beginning.)
>20MHz and 40MHz are "Ultra" SCSI speeds (FAST-20 and FAST-40; UltraStor
>holds a TM/patent on "UltraSCSI") and your /proc output indicated ultra
>scsi was disabled.
>
>If in doubt, test the transfer speed with 'hdparm -Tt'
>
>--Ricky
>
>
>To Unsubscribe: send mail to majordomo at FreeBSD.org
>with "unsubscribe aic7xxx" in the body of the message
>
>

Steven A. Swanson
Budco - The Dialogue Company
Information Technologies
13131 Lyndon
Detroit, MI 48227

office   313.933.3285
fax      313.933.7990
pager    810.485.1111


To Unsubscribe: send mail to majordomo at FreeBSD.org
with "unsubscribe aic7xxx" in the body of the message