IDE controllers -- compatible?

[larrymoencurly]

If I partiton and format an HD with one brand of IDE controller, will
it be readable under Windows with other brands of controller?

I ask because there used to be compatibility problems among some mobos
and their IDE controllers because of BIOS differences, I don't want to
be left high and dry if I have an oddball PCI IDE controller fail.

I'm mostly concerned about Promise, SIIG, and Silicon Image PCI IDE
cards. I realize that they use different Windows drivers.

 

[Arno Wagner]

If I partiton and format an HD with one brand of IDE controller, will
it be readable under Windows with other brands of controller?

I ask because there used to be compatibility problems among some mobos
and their IDE controllers because of BIOS differences, I don't want to
be left high and dry if I have an oddball PCI IDE controller fail.

I'm mostly concerned about Promise, SIIG, and Silicon Image PCI IDE
cards. I realize that they use different Windows drivers.

As long as you use LBA, there will not be a problem (unless the
implementation is buggy). With any type of CHS you might get
problems, since it can be different for different BIOS.

RAID is a different story, here vendors are intentionally (at
least that is what I think) incompatible.

Arno

 

[Folkert Rienstra]

As long as you use LBA,

Well, there isn't much choice, is there. It's the operating system
or program that decides whether CHS or LBA addressing is used.

there will not be a problem (unless the implementation is buggy).

What implementation.

With any type of CHS you might get problems,

Clueless Arnie again. LBA as found in the MB bios *IS* about CHS.
It is called LBA-assist translation (as opposed to Large or Normal
CHS translation).

The bios settings are all about CHS, they decide how the bios Int13
CHS call will translate into the drive interface CHS or LBA command.

To address a drive in LBA the Int13ext call must be used.
It doesn't need settings as there will not be any translation.

since it can be different for different BIOS.

Only if the bios behaves in a way that it shouldn't.

The BIOS should read the info from the MBR, not from it's settings.
The settings come in effect when a prestine drive needs partitioning.

With current large drives the CHS is only important for booting (Int19).
On non-bootable drives the CHS is mainly ignored (well, at least with
Windows9x and FAT32 it is).
Some NT flavor drivers appear to have problems if the large drive place
holder CHS values (values that signal that the drive is over 8GB) aren't
used (see Svend's 32GB problem). There also was a problem with a drive
that offered 15-head translation instead of 16-head translation where
an NT flavored Windows wouldn't recognize the drive as bigger than 8GB.

Oh, and the add-in IDE cards usually don't even offer translation settings.

 

[Rob Nicholson]

RAID is a different story, here vendors are intentionally (at

least that is what I think) incompatible.

Although if you stay within the same manufacture (e.g. Promise) then you
stand a reasonable high chance of the RAID arrays being recognised,
especially if upgrading up.

Cheers, Rob.

 

[Odie Ferrous]

Well, there isn't much choice, is there. It's the operating system
or program that decides whether CHS or LBA addressing is used.

Not the BIOS?

Odie

 

[Eric Gisin]

Not the BIOS?

The BIOS provides both CHS and LBA Int13's. How is that supposed to help the OS
choose?

 

[CJT]

The BIOS provides both CHS and LBA Int13's. How is that supposed to help the OS
choose?

Is there any BIOS clever enough to boot from the area on the disk above
where long addressing is needed?

 

[Folkert Rienstra]

Is there any BIOS clever enough to boot from the area on the disk above
where long addressing is needed?

It's not the BIOS that needs to be 'clever', it's the secondary bootloader in
the MBR. If that would use Int 13h ext. then it will boot beyond 8 GB just fine.

 

[Folkert Rienstra]

Not the BIOS?

Apparently only Int 19h (system bootstrap loader) and the MBR boot
loader use CHS (Int 13h) by default.
Int 13h uses CHS, Int 13h ext. uses LBA for input, the OS decides which
Int 13h or OS Int 13h comparable call to use depending on the program call.

As I said before, the only thing the bios has a say in is in how an
Int 13h CHS (L-CHS) is translated into a drive CHS (P-CHS) or LBA.

From experiment you can change the CHS in the partition tables of
logical drives and they will still be recognized (presumably restrict-
ed to Int 13h ext. compatible partition types). However, if you do
that to the bootdrive (primary partition) then it will fail to boot.

 

[Eric Gisin]

Is there any BIOS clever enough to boot from the area on the disk above
where long addressing is needed?

Which long addresses?

The BIOS always loads LBA=0, CHS=001. All recent Windows install an MBR that
loads any partition boot sector using CHS or LBA.

 

[John Turco]

Although if you stay within the same manufacture (e.g. Promise) then you
stand a reasonable high chance of the RAID arrays being recognised,
especially if upgrading up.

Cheers, Rob.

Hello, Rob:

I believe "upgrading up" is rather redundant, don't you? ;-)


Cordially,
John Turco <[email protected]>