Using a 48 bit LBA HD on a comp without 48 bit LBA bios support

[nil_einne1]

Hey all,

Helping a friend upgrade their comp. Unfortunetely it has a Asus P2B
motherboard with a 440BX and so doesn't have 48 bit LBA support (last
bios is a beta release in 2002 but they didn't bother or couldn't
enable 48bit LBA support). My friend doesn't really need that much
space but given the ridiculous price of 120 gb HDs, I would really like
to avoid them (a 160gb HD cost about ~8.5% more). Using only 137gb (128
real gb) of a 160gb HD will turn out to be cheaper/gb then using a
120gb HD and there will also be the advantage of the extra capacity
available should there ever be an upgrade (unlikely though).

I've been doing some testing with a 160gb HD and reading and as far as
I can tell, using only 137gb (128 real gb) of the HD i.e. disabling
48bit LBA support in Windows should be fine even without proper bios
support. The bios detects the HD I've been testing as a 8gb and I'm
likely to be buying a Seagate HD which doesn't have the ability to
limit to 128gb so I suspect this will be similar. But as said, as far
as I can tell this should not cause any problems nor should there ever
be any risk I think. Can anyone clarify/confirm?

BTW, interestingly, I've tried enabling 48bit LBA support in Windows
and using the extra capacity and there was no data corruption. Go
figure! But this is a bit too risky for me even though it seemed fine
so I'm not interested in trying it.

Also a SATA or ATA raid card is not being considered since it's noth
worth it given my friends need.

Cheers and thanks for help all

 

[Yves Leclerc]

You do not have to buy a RAID card. Just a plain ATA/133 or SATA add-in
card will give you the max caacity the drives would allow.

 

[Anna]

You do not have to buy a RAID card. Just a plain ATA/133 or SATA add-in
card will give you the max caacity the drives would allow.

Well, although you stated that your friend doesn't want to invest in a
RAID-supported controller card, I assume from that that he or she similarly
doesn't want to purchase *any* controller card which would yield
large-capacity disk support. So I suspect Yves' suggestion may not be
practical in your situation although frankly it *would* do the job at a
relatively small cost - about $35 or so and really be the best solution,
assuming there was a real need for the system to recognize the full capacity
of the disk..

As a practical matter, it probably would be best if your friend installs the
160 GB (or larger) drive and simply live with the fact that the system will
recognize (approx) 128 GB (137 GB decimal) of the drive. There is a kind of
workaround - see
http://support.microsoft.com/default.aspx?scid=kb;en-us;303013, but it's
kind of iffy and I wouldn't recommend it on a day-to-day basis. There are
also so-called "large disk enablers" (or some such) available from some HD
manufacturers - Maxtor probably being the most popular, but it's another
"workaround" I discourage. They make non-standard, proprietary changes in
the registry and elsewhere in the system that are nearly certain to cause
future problems. No doubt your friend could live with the truncated capacity
of a large-capacity drive in his or her present system and, as you say,
later use the drive in an updated system.

BTW, make sure SP2, or at least SP1 has been installed.
Anna

 

[Vanguard \(NPI\)]

Well, although you stated that your friend doesn't want to invest in a
RAID-supported controller card, I assume from that that he or she
similarly doesn't want to purchase *any* controller card which would yield
large-capacity disk support. So I suspect Yves' suggestion may not be
practical in your situation although frankly it *would* do the job at a
relatively small cost - about $35 or so and really be the best solution,

I got a Promise Ultra100 TX at eBay for $5 (plus $5 shipping). The hard
drive makers were sliding in an IDE controller card inside the packaging for
their retail drives but which the user didn't need because their mobo's BIOS
supported the large drive. So they dump them on eBay. Come to think of it,
I recall yanking it out of an old host and now it collects dust in a drawer
in an anti-static bag along with the driver diskette.

They are still selling damn cheap at eBay (but watch the shipping cost to
make sure the seller doesn't rip you off that way). If the user can't
afford $10 for an IDE controller card, they probably shouldn't be spending
money on a large hard drive in the first place.

 

[Vanguard \(NPI\)]

Well, although you stated that your friend doesn't want to invest in a
RAID-supported controller card, I assume from that that he or she
similarly doesn't want to purchase *any* controller card which would yield
large-capacity disk support. So I suspect Yves' suggestion may not be
practical in your situation although frankly it *would* do the job at a
relatively small cost - about $35 or so and really be the best solution,
assuming there was a real need for the system to recognize the full
capacity of the disk..

As a practical matter, it probably would be best if your friend installs
the 160 GB (or larger) drive and simply live with the fact that the system
will recognize (approx) 128 GB (137 GB decimal) of the drive. There is a
kind of workaround - see
http://support.microsoft.com/default.aspx?scid=kb;en-us;303013, but
it's kind of iffy and I wouldn't recommend it on a day-to-day basis. There
are also so-called "large disk enablers" (or some such) available from
some HD manufacturers - Maxtor probably being the most popular, but it's
another "workaround" I discourage. They make non-standard, proprietary
changes in the registry and elsewhere in the system that are nearly
certain to cause future problems. No doubt your friend could live with the
truncated capacity of a large-capacity drive in his or her present system
and, as you say, later use the drive in an updated system.

Oops, forgot about another solution - and a free one. Install the drive
manager overlay that the drive maker provides. It usurps the bootstrap area
in the MBR (first sector of the drive) to load and manage the drive which is
oversized for the system BIOS. The BIOS loads and passes control to the
bootstrap program in the MBR bootstrap area and the bootstrap program reads
the partition table to determine which partition's boot sector to load to
begin the operating system. So the drive overlay simply replaces the MBR
bootstrap program loads a BIOS extension to allow the full capacity of the
hard drive that the system BIOS couldn't handle.

The drive overlay is free. Just visit the drive maker's web site for the
download. Since the OP never identified WHICH drive manufacturer from which
they will get the oversized hard drive, they cannot be given a URL to the
download (i.e., they'll have to do their own web hunting).

 

[Andy]

Hey all,

Helping a friend upgrade their comp. Unfortunetely it has a Asus P2B
motherboard with a 440BX and so doesn't have 48 bit LBA support (last
bios is a beta release in 2002 but they didn't bother or couldn't
enable 48bit LBA support). My friend doesn't really need that much
space but given the ridiculous price of 120 gb HDs, I would really like
to avoid them (a 160gb HD cost about ~8.5% more). Using only 137gb (128
real gb) of a 160gb HD will turn out to be cheaper/gb then using a
120gb HD and there will also be the advantage of the extra capacity
available should there ever be an upgrade (unlikely though).

I've been doing some testing with a 160gb HD and reading and as far as
I can tell, using only 137gb (128 real gb) of the HD i.e. disabling
48bit LBA support in Windows should be fine even without proper bios
support. The bios detects the HD I've been testing as a 8gb and I'm
likely to be buying a Seagate HD which doesn't have the ability to
limit to 128gb so I suspect this will be similar. But as said, as far
as I can tell this should not cause any problems nor should there ever
be any risk I think. Can anyone clarify/confirm?

Once Windows has been booted and is running, the BIOS plays no role
when Windows accesses the hard drive.

BTW, interestingly, I've tried enabling 48bit LBA support in Windows
and using the extra capacity and there was no data corruption. Go
figure! But this is a bit too risky for me even though it seemed fine
so I'm not interested in trying it.

If Disk Management shows the correct disk capacity of the hard drive,
then the operating system will properly access the entire drive.