dumb question

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Built a machine with Asus mobo, harddrives are mixed, one is an SATA running
at 10,000 rpms this what I boot off of. The other is 7200 rpm ata. machine
works like a charm. Like to add a 3rd hd 15000 rpm scsi, shouldn't be a
problem mixing HDs ATA and Scsi correct?


Re: dumb question

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No, the SCSI should run off a pci slot adaptor card OK.

Re: dumb question

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Re: dumb question

peter wrote:
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If the SCSI disk is just for data, little can go wrong.

If you want to boot from the SCSI disk, the PCI controller card
you use for the SCSI, will have a BIOS to load. The motherboard
BIOS must be able to properly accept the SCSI drive as a boot
option. And also there must be enough low memory, for the SCSI
BIOS to load. Under exceptional circumstances (all PCI slots
filled with controller cards), sometimes not all the controllers
can load their BIOS.

So as a data disk, there should be little challenge to setting it
up. If you want to boot from it, again, it shouldn't be impossible,
but there are things that can go wrong. The following is something
I found on forums.2cpu.com, about how add-in card BIOSes work.


    Q: Why doesn't the BIOS (Option ROM) for my PCI device show
       during boot up?

    A: The cause of the problem is that in order to be PC Compatible,
       the Option Rom space is limited to 128K. This is true for any
       motherboard with PC compatible BIOS'.

       In the common configurations, a newer AGP card (such as any
       GeForce4) will require 64K of Option Rom space, so you have only
       64K of Option Rom space left to work with for other devices.
       Many SCSI, NIC (w/ PXE), IDE Raid and etc., can easily use
       another 40 to 64K of Option Rom space for their needs.

       By design the Option Rom should shrink down to a smaller run time
       code after the initialization code has run. For example, some Adaptec
       cards will require 32K to initialize. Then they shrink down to
       12K at run time; whereas some GeForce4 cards require 64K to initialize
       and never release to a smaller amount. Please check with the device
       manufacturer for the latest firmware upgrade or ask if they have a
       smaller Option Rom available. Again this is a limitation of the
       PC compatible specification and not a failure of the motherboard
       BIOS itself.


Re: dumb question

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_Shouldn't_ be a problem.  Most BIOS's nowadays have option to
place SCSI booting whereever you'd like in the boot sequence (or
indeed, not have it in the boot sequence at all).  The only other
gotcha is possibly your OS - I recall some versions of SCO Unix
used to need a little tweaking in mixed ATA/SCSI installations but
nothing insurmoutable.  I wouldn't expect problems nowadays though
- in particular, SCSI disks and ATA optical drives seem a much more
popular combo than they were in the past, due to the limited range
and high price of SCSI equivalents.

Andrew Smallshaw

Re: dumb question

Think again.  You would be setting up a complex system for your BIOS to


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Re: dumb question

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THe BIOS wouldn't give a shit.


Light travels faster than sound. This is why some people appear bright
until you hear them speak.........

Re: dumb question

On Wed, 31 Jan 2007 15:39:56 -0800, "DaveW"

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Yeah, let's all go out of our way to not make things
"complex" for a bios.  It would be easier for our struggling
bios to not have a mouse or keyboard, or any hard drives at
all, right?  If we disconnect the PSU we won't have to worry
about anything, the bios has it made in the shade then.

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