SCSI connectivity

From: Chad Fernandez <fernande_at_internet1.net>
Date: Sat Mar 10 23:59:29 2001

ajp166 wrote:
> >ISA 1542B installed. I haven't actually gotten the computer up yet....
> >still have some IRQ/DMA conflicts, I think.
>
> Likely. Then again I set those things up in my sleep.

I did a MB swap but only went over the jumpers on the MB, not the
jumpers on the cards. I'll get to it, as soon as I get around to
it..... really the main thing is getting the 1540 to work with the
onboard 1520.

> >SCSI is backwards compatible as long as you keep Single Ended and
> >Differential separate.
>
> Thanks for the info... I only work with them for a lving. ;)

You work with Differential (not LVD) every day? What do you do?
 
> >I would think any high end 486 class machine
> >would benefit from wide scsi. Remember SCSI doesn't rely on the CPU
> >like IDE does.
>
> No. No. I retired an old P133 server that had a Wide SCSI card in it..
> With the 33mhz FSB there was little hope of using all the performance
> of the SCSI-W nor the really fast disk 7200rpm disk hooked to it. With
> VLB or EISA your likely talking a 486DX4/133 maximum and they
> are even slower. I know I have a 5x86/133 with VESA and the best
> I see on that one is maybe 30mb/sec and that the burst rate not
> an average.

How did you get 30mb/sec out of a 20mb/sec capable hardware setup?
Narrow is 5, 8, or 10, ultra narrow is 20, wide is 20, ultra wide is 40
and U2W is 80, and U3W (U160) is 160. What VLB card is wide? I don't
think Adaptec has one, do they? I would like to get a VLB wide scsi
card for the computer mentioned above.

What do you use for drive benchmark testing? I use Snooper, but I never
get anywhere near the speeds that are advertised. I figure that Snooper
must use some sort of average, and I only compare Snooper results with
other Snooper results. For instance my UW drive on this computer checks
in at 5,xxx Kb/sec, but should be able to hit 40megs/sec, actually 80 if
I had an LVD cable. Its on a 2940U2W.

>
> >I actually have a pair of 8-bit SCSI cards, a Seagate, and an NCR. I
> >have used the Seagate, unfortunately it didn't see more than 2xx of the
> >300megs of my HD, after I repartitioned the HD on that controller. I
>
> That and the best data rate will be 8-10mb/sec. ISA isn't fast.
> Win95 if you have the OEM disk has drivers for some pretty old and
> oddball stuff.

I need to rephrase that, the cards are 8-bit ISA, not 8-bit SCSI.
 
> Maybe the point I'm making is just getting them going is often all that
> can be asked. Trying to go for maximum smpoke is often not worth
> it as recent hardware is cheap and far faster.

I am not trying to be rude, or make enemies, but why are you on a
classic computer list? Sure I want my old computers to run, but I want
it to be a fast as I can get it, while maintaining reliably.

Chad Fernandez
Michigan, USA
Received on Sat Mar 10 2001 - 23:59:29 GMT