No worries.
You should still be able to set the BIOS to negotiate with the drive up
to it's maximum interface speed. I missed the original posts of this
message, but is it true that this is an LVD interface (80 MB/sec). I
was just saying that you won't actually be able to copy data to the
drive at that sustained throughput. I have no experience with the LVD
drives. I just wanted to say that I haven't any problems with the 9ZX -
I would personally recommend it. And for what it is worth I am using the
ASUS P2BS motherboard with the onboard AIC-7890 UW/LVD controller.
Previous to the RedHat 5.2 release it was kind of flacky. Are you using
the latest build of the driver? I had trouble getting everything patched
corectly so I just went out and bought the 5.2 Redhat and it installed
correctly. I have the 9ZX in a removable drawer and I take it home and
use it on a machine with the 2940UW card at home. I even have internal
automatic termination set on the that unit (which I guess is asking for
trouble).
Personally I have been avoiding the LVD drive interfaces. The UW2 is
fast enough for me (since I usually only have 1 drive, and at most 2, on
the bus). It is a common mistake to confuse interface speed with
sustained throughput of the drive. The interface transfer rateis the
maximum transfer rate that the controller can negotiate with the drive
(80MB/sec LVD, 40MB/sec UW2), and the sustained throughput of the device
is limited by the media transfer rate (how fast the data can be
physically written to the drive). With multiple devices on the bus
having high interface transfer rates is great when it works 'cause you
can service the SCSI targets that much faster. With just one SCSI target
it is a wash. I am by no means an expert on this. I assume you have
tried this drive alone.
-Eric
Charles Galpin wrote:
>
> please excuse my ignorance, but this is my first experience with SCSI...
>
> ===== Original Message from Eric Hegstrom <[EMAIL PROTECTED]> at
> 4/21/99 10:47 am
> >Well lloking at that URL, I see thatthe Maximum Interface transfer rate is 80
> >MB / sec, but the Media transfer rate 108.6 to 171.1 Mbits / sec which is
> >13.575 - 21.3875 MB/sec.
>
> Ok, what is the net result? that I can only expect 13.575 - 21.3875 MB/sec
> and to set the BIOS accordingly? I tried 13.5 and 10 MB without luck, and
> would say that for this speed perhaps this U2W controller/drive is not worth
> it!
>
> >
> >I have the 10200 RPM wide version of this drive (the IBM Ultrastar 9ZX I
> >beleive) and I have 2 systems (one with an internal AIC-7890 Adaptec UW/LVD,
> >the other with a 2940UW). The drive works great in both systems. I am able to
> >get almost 18MB/sec sustained transfer rate for streaming. I remember just a
> >few years ago when we needed to buy $8K RAID arrays at work to get 12MB+/sec.
>
> is this one of those integrated into an P2Bs? I considered going that route,
> but figured it ould be better to have a seperate adapter and get a less
> expensive AMD cpu now, and later upgrade if I want.
>
> >Oh yea, I am using the Redhat 5.2 install (I think it is kernel 2.0.32 but I am
> >not sure)
> >
> >Peace,
> >Eric
>
> -- Charles Galpin <[EMAIL PROTECTED]>
--
Eric Hegstrom .~.
Senior Software Engineer /V\
Sonoran Scanners, Inc. // \\ L I N U X
[EMAIL PROTECTED] /( )\ >don't fear the penguin<
520-617-0072 x402 ^^-^^
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