SCSI hard drives on ordinary mainboards?

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John Doe

How difficult/easy is setting up a SCSI hard drive on an ordinary
mainboard? Anybody have actual experience with that?

Mostly curious, thanks.
 
John said:
How difficult/easy is setting up a SCSI hard drive on an ordinary
mainboard? Anybody have actual experience with that?

Mostly curious, thanks.
Click to expand...

I have a P2B-S (440BX), which has SCSI built into the motherboard.
That was a good era to be interested in SCSI, because you
could get a SCSI interface for pretty cheap, soldered right
to the motherboard. With modern motherboards, you'd need
an add-in card instead. And if you were interested in running
a 320MB/sec SCSI bus, you need a motherboard bus that will
not be a bottleneck (like PCI-X which is common on server
boards).

If you are interested, the first thing to do, is look around
for a cheap controller. Buying new at retail, they can cost
hundreds of dollars. Occasionally, the mythical "$50 card"
will show up, and some of those are almost impossible to
find drivers for. So that is one part of the fun, tracking
down a card that has drivers, is not a bottleneck, and plugs
into your desktop. (An Asus "workstation" motherboard, with
some more useful slots on it, might be a good platform for
a 320MB/sec SCSI controller.)

For drives, there will be a wide range of "pulls", removed
from server operation and available for sale. Some of those
will be worn out, so you'd have a lot of bearing noise (because
the old ones wouldn't have fluid drive bearings). Also,
some server drives have such bad noise characteristics,
that you could not stand to keep them in a desktop. (A certain
IBM drive, does self test every 71 seconds, and makes a screeching
noise.) So, while you may see "bargains" in the form of pulls, they
are not all good prospects.

The most challenging part, is getting the cabling and terminations
set up right. There are wide and narrow drives, automatic or manual
terminations on enclosures, ribbon cables for internal connections,
expensive cables for external, and so on. The controller card
should be no more difficult to install than putting an IDE
card in your computer.

The latest version, SAS, should be a bit tamer than the older
technologies. The physical interface, is the same thing as SATA,
and uses that thin cable.

http://en.wikipedia.org/wiki/Serial_Attached_SCSI

And from this article, for the older stuff,

http://en.wikipedia.org/wiki/Scsi

I found this guide.

http://www.delec.com/guide/scsi/

If you have deep pockets, these guys carry SCSI.

http://www.granitedigital.com/catalog/indx_scsi.htm

Storagereview lists this one as 135MB/sec sustained transfer,
at the beginning of the disk. The 320MB/sec bus transfer, would
happen for bursts to cache. I don't know what the noise is like
on one of these.

http://www.seagate.com/docs/pdf/datasheet/disc/ds_cheetah_15k_5.pdf

300GB for only $930
https://www.serversupply.com/products/part_search/query.asp?q=ST3300655LW&pw=Y

By comparison, one or more Raptors seems so much more reasonable.
Only the seek time cannot be matched.

Paul
 
Paul said:
I have a P2B-S (440BX), which has SCSI built into the motherboard.
That was a good era to be interested in SCSI, because you
could get a SCSI interface for pretty cheap, soldered right
to the motherboard. With modern motherboards, you'd need
an add-in card instead. And if you were interested in running
a 320MB/sec SCSI bus, you need a motherboard bus that will
not be a bottleneck (like PCI-X which is common on server
boards).

If you are interested, the first thing to do, is look around
for a cheap controller. Buying new at retail, they can cost
hundreds of dollars. Occasionally, the mythical "$50 card"
will show up, and some of those are almost impossible to
find drivers for. So that is one part of the fun, tracking
down a card that has drivers, is not a bottleneck, and plugs
into your desktop. (An Asus "workstation" motherboard, with
some more useful slots on it, might be a good platform for
a 320MB/sec SCSI controller.)

For drives, there will be a wide range of "pulls", removed
from server operation and available for sale. Some of those
will be worn out, so you'd have a lot of bearing noise (because
the old ones wouldn't have fluid drive bearings). Also,
some server drives have such bad noise characteristics,
that you could not stand to keep them in a desktop. (A certain
IBM drive, does self test every 71 seconds, and makes a screeching
noise.) So, while you may see "bargains" in the form of pulls, they
are not all good prospects.

The most challenging part, is getting the cabling and terminations
set up right. There are wide and narrow drives, automatic or manual
terminations on enclosures, ribbon cables for internal connections,
expensive cables for external, and so on. The controller card
should be no more difficult to install than putting an IDE
card in your computer.

The latest version, SAS, should be a bit tamer than the older
technologies. The physical interface, is the same thing as SATA,
and uses that thin cable.

http://en.wikipedia.org/wiki/Serial_Attached_SCSI

And from this article, for the older stuff,

http://en.wikipedia.org/wiki/Scsi

I found this guide.

http://www.delec.com/guide/scsi/

If you have deep pockets, these guys carry SCSI.

http://www.granitedigital.com/catalog/indx_scsi.htm

Storagereview lists this one as 135MB/sec sustained transfer,
at the beginning of the disk. The 320MB/sec bus transfer, would
happen for bursts to cache. I don't know what the noise is like
on one of these.

http://www.seagate.com/docs/pdf/datasheet/disc/ds_cheetah_15k_5.pdf

300GB for only $930
https://www.serversupply.com/products/part_search/query.asp?q=ST3300655LW&pw=Y

By comparison, one or more Raptors seems so much more reasonable.
Only the seek time cannot be matched.

Paul
Click to expand...

Look on ebay faor AHA2940, (Adaptec) XP has inbuilt drivers.

Mike.
 
John Doe said:
How difficult/easy is setting up a SCSI hard drive on an ordinary
mainboard? Anybody have actual experience with that?

Mostly curious, thanks.
Click to expand...

Trying to interpret your question the way you want it to be interpreted...

By "ordinary mainboard", am I correct to assume that you mean a m/b that
doesn't already have onboard SCSI?

If so, you'll need a controller card, obviously.

Back in the P3 days, that was I used: dual-P3 m/b's with onboard SCSI.
Onboard SCSI is, of course, less involved than using a controller card.
With onboard SCSI, you can always be assured that you will be able to boot
from SCSI, while with a controller card you'll want to read reviews
carefully to ensure that you will be able to do so. (Most do, especially
these days.)

SCSI isn't as difficult as some make it out to be. In fact, in days past, I
always found SCSI to be easier to work with than IDE. The two main rules
are simply to assign every device (on same channel) a unique ID (jumper
settings on device) and the ends of each bus needs to be terminated. The
"bus" is the physical cable(s). Even if several cables make up different
segments on the same channel, they all need to be terminated at both ends.
Termination absorbs the electrons and RF so they don't reflect back down the
cable. The "termination question" often gets more involved than need be:
just remember to terminate according to the physical layouts, not logical.

With just one device (HDD) and a controller card, it is very straight
forward. The controller will have an ID of 7. Set the HDD for an ID of 0.
Enable termination on the controller. The other end of the LVD cable will
likely already have a term built-in, so you don't need to enable term on the
HDD. Thats it.

For all the nitty-gritty, look for the "The Book of SCSI". I have a copy of
the 2nd edition laying around here somewhere that was helpful in the past.
 
John Doe said:
How difficult/easy is setting up a SCSI hard drive on an ordinary
mainboard? Anybody have actual experience with that?
Click to expand...

Done a few; no insurmountable problems...

First, make sure your SCSI adapter [card] directly supports the HD you buy.
There are various pinouts, and pin adapters may not work well or at all.

Understand that some SCSI cards have a BIOS that is accessible on boot-up,
right after your regular BIOS. If yours has one, you may have to tweak some of
the settings, especially if the SCSI HD will be your boot drive.

Finally, realize that these days SCSI will likely only give you a performance
advantage over SATA or IDE if at least one of the following is true:

Your SCSI drives are faster (10K or 15K RPM) than the others
Your SCSI card is on a 64-bit PCI bus
You use RAID 0, 5, or 10 on the SCSI
 
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