J
Jonny
Hmm, odd you didn't mention any service packs for XP like SP1 or SP2.
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S
sarmadgilani
Hi,
I've got an old MSI Gateway-OEM motherboard (MS-6330) that doesn't
support 48-bit LBA with its latest BIOS revision, so my Western Digital
250GB drive shows up as 137GB in BIOS, as expected.
But, in Windows, Disk Management shows it as the full 232 GB, and I'm
able to create >137GB partitions, format, and use them.
Is this safe to use without messing with drive overlays? I'm not going
to boot from the drive, it'll be used for storage only.
Thanks!
I've got an old MSI Gateway-OEM motherboard (MS-6330) that doesn't
support 48-bit LBA with its latest BIOS revision, so my Western Digital
250GB drive shows up as 137GB in BIOS, as expected.
But, in Windows, Disk Management shows it as the full 232 GB, and I'm
able to create >137GB partitions, format, and use them.
Is this safe to use without messing with drive overlays? I'm not going
to boot from the drive, it'll be used for storage only.
Thanks!
S
sarmadgilani
Oops, sorry.. I've got SP2. So I know that Windows can support the
drive just fine, but I want to make sure that my BIOS limitations won't
hurt me.
I would think that Windows doesn't care that the BIOS only reports 137
GB, since it correctly detected the whole drive. But I'm not sure about
data loss or corruption in the future... I would think that BIOS is
irrelevant in this case?
drive just fine, but I want to make sure that my BIOS limitations won't
hurt me.
I would think that Windows doesn't care that the BIOS only reports 137
GB, since it correctly detected the whole drive. But I'm not sure about
data loss or corruption in the future... I would think that BIOS is
irrelevant in this case?
D
DL
There is I believe a theoretical possibility of data lose/corruption.
Incidentally, this also applies if a large drive is formated to 137gb, then
large Lba is enabled and then in the subsequent free space another partition
is created.
(Read this on some Win tech paper)
Incidentally, this also applies if a large drive is formated to 137gb, then
large Lba is enabled and then in the subsequent free space another partition
is created.
(Read this on some Win tech paper)
S
sarmadgilani
I've looked at KB articles and the like, and I can't even find a
reference to a situation where the BIOS only supports 32-bit LBA, but
that Windows can detect the full size.
I guess it comes down to whether or not Windows cares about the
translated geometry that BIOS gives it.. seems like it is disregarding
what BIOS reports since it can see and access the whole drive. At least
I think that's the case... wish I could find a straight answer though!
reference to a situation where the BIOS only supports 32-bit LBA, but
that Windows can detect the full size.
I guess it comes down to whether or not Windows cares about the
translated geometry that BIOS gives it.. seems like it is disregarding
what BIOS reports since it can see and access the whole drive. At least
I think that's the case... wish I could find a straight answer though!
D
DL
If your bios specifically states it supports HD's up to a certain size it
maybe because at the time of release it wasnt envisaged that there would be
any larger HD's and as such it wasnt tested on anything larger.
I would, however, remain wary upon relying on the integrity of any data.
maybe because at the time of release it wasnt envisaged that there would be
any larger HD's and as such it wasnt tested on anything larger.
I would, however, remain wary upon relying on the integrity of any data.
A
Andy
Once Windows has been booted and is running, the BIOS is irrelevant
when Windows accesses the hard drives.
when Windows accesses the hard drives.
J
Jonny
Its 28 bit LBA on the older bios versions.
S
sarmadgilani
That's what I thought too; BIOS shouldn't matter after the system is
booted up. I would think that I only have to worry if I wanted to make
bootable partition that spans the 137 GB boundary, since in that case
BIOS needs to access it correctly.
booted up. I would think that I only have to worry if I wanted to make
bootable partition that spans the 137 GB boundary, since in that case
BIOS needs to access it correctly.
K
kenny
Can you give us proof of this claim?
Andy said:Once Windows has been booted and is running, the BIOS is irrelevant
when Windows accesses the hard drives.
C
cquirke (MVP Windows shell/user)
Can you give us proof of this claim?
I think it's based on the assumption that within Win9x GUI, all HD
access will be handled by Windows drivers, not BIOS calls.
The operative word there is "all". If there are any contexts where
BIOS calls are used instead, especially to write to HD, you'd be in
trouble. As it is, you are out in the cold in DOS mode ("Restart in
MS-DOS") and Safe Mode, as neither of these invoke Windows drivers to
access HD and both of these rely on BIOS.
Also, should the system fall into DOS Compatibility Mode for any
reason - where normal Windows "runs on top of DOS" for disk services,
thus relying on BIOS - you'd be in trouble again.
Windows is a fair-whether-friend at the best of times; it needs a lot
offiles to be intact to run, and it always writes to the HD. If
running > 137G on a BIOS that doesn't support > 137G, you'd be as
exposed as XP on NTFS or FAT16 on ye olde disk compression if things
would go wrong in any significant way (e.g.Windows won't boot).
Tip Of The Day:-------------------- ----- ---- --- -- - - - -
To disable the 'Tip of the Day' feature...
A
Anna
Can you give us proof of
this claim?
The background to all this is that the OP maintained that while his 250 GB
HD was recognized to its full capacity by the OS, his (apparently) elderly
BIOS did not recognize large-capacity drives, i.e., disks > 137 GB.
Apparently Kenny was challenging this claim, and with good reason it would
seem to me.
Since the OP did not indicate as such, we'll set aside the possibility that
his or her large-capacity drive in question was connected to a controller
card that was capable of recognizing large-capacity drives and assume that
the drive was directly connected to one of the motherboard's IDE connectors.
And we'll further assume that no "drive overlay" program providing
large-capacity disk capability had been grafted onto the drive. With those
provisos, to the best of my knowledge, if the motherboard's BIOS does not
support large-capacity drives, there's no way that the XP OS could.
Anna
this claim?
I think it's based on the assumption that within Win9x GUI, all HD
access will be handled by Windows drivers, not BIOS calls.
The operative word there is "all". If there are any contexts where
BIOS calls are used instead, especially to write to HD, you'd be in
trouble. As it is, you are out in the cold in DOS mode ("Restart in
MS-DOS") and Safe Mode, as neither of these invoke Windows drivers to
access HD and both of these rely on BIOS.
Also, should the system fall into DOS Compatibility Mode for any
reason - where normal Windows "runs on top of DOS" for disk services,
thus relying on BIOS - you'd be in trouble again.
Windows is a fair-whether-friend at the best of times; it needs a lot
offiles to be intact to run, and it always writes to the HD. If
running > 137G on a BIOS that doesn't support > 137G, you'd be as
exposed as XP on NTFS or FAT16 on ye olde disk compression if things
would go wrong in any significant way (e.g.Windows won't boot).
Tip Of The Day:
To disable the 'Tip of the Day' feature...
The background to all this is that the OP maintained that while his 250 GB
HD was recognized to its full capacity by the OS, his (apparently) elderly
BIOS did not recognize large-capacity drives, i.e., disks > 137 GB.
Apparently Kenny was challenging this claim, and with good reason it would
seem to me.
Since the OP did not indicate as such, we'll set aside the possibility that
his or her large-capacity drive in question was connected to a controller
card that was capable of recognizing large-capacity drives and assume that
the drive was directly connected to one of the motherboard's IDE connectors.
And we'll further assume that no "drive overlay" program providing
large-capacity disk capability had been grafted onto the drive. With those
provisos, to the best of my knowledge, if the motherboard's BIOS does not
support large-capacity drives, there's no way that the XP OS could.
Anna
C
cquirke (MVP Windows shell/user)
The background to all this is that the OP maintained that while his 250 GB
HD was recognized to its full capacity by the OS, his (apparently) elderly
BIOS did not recognize large-capacity drives, i.e., disks > 137 GB.
Apparently Kenny was challenging this claim, and with good reason it would
seem to me.
OK...
Since the OP did not indicate as such, we'll set aside the possibility that
his or her large-capacity drive in question was connected to a controller
card that was capable of recognizing large-capacity drives and assume that
the drive was directly connected to one of the motherboard's IDE connectors.
And we'll further assume that no "drive overlay" program providing
large-capacity disk capability had been grafted onto the drive. With those
provisos, to the best of my knowledge, if the motherboard's BIOS does not
support large-capacity drives, there's no way that the XP OS could.
XP could, but that would only work if:
- all boot code and files lie within first 137G
- XP is SP1, preferably SP2
XP SP0 can't work here, period. SP1 can, but is not safe in all
contexts, even if BIOS is LBA-48-safe (IOW, the problem is not one of
fall-through to BIOS, but inbuilt LBA-48-bad logic that is called in
certain very particular contexts). SP2 fixes the flaws in SP1's
attempted support for > 137G HDs.
Other threads elsewhere are contending that even Win9x can work on >
137G HDs, as long as all volumes are < 137G and appropriate HD
controller drivers are in effect. This is even more brittle, as
several contexts in Win9x do indeed fall through to BIOS, i.e. Safe
Mode, DOS compatibility mode, and DOS mode itself.
Don't pay malware vendors - boycott Sony---------- ----- ---- --- -- - - - -
A
Anna
Anna
cquirke:
I mean no offense, but I find your comments impenetrable at least with
respect to responding to specific points you have raised. So let me
reiterate my previous statement...
If a user's motherboard's BIOS does *not* support large-capacity disks,
i.e., drives > 137 GB and the user's hard drive is directly connected to the
motherboard, i.e., no HD controller card or drive overlay program is in play
here, then the XP OS, REGARDLESS of whether that OS includes SP1 and/or SP2,
WILL NOT RECOGNIZE THE FULL CAPACITY OF A DRIVE > 137 GB. Period.
Anna
cquirke (MVP Windows shell/user) said:XP could, but that would only work if:
- all boot code and files lie within first 137G
- XP is SP1, preferably SP2
XP SP0 can't work here, period. SP1 can, but is not safe in all
contexts, even if BIOS is LBA-48-safe (IOW, the problem is not one of
fall-through to BIOS, but inbuilt LBA-48-bad logic that is called in
certain very particular contexts). SP2 fixes the flaws in SP1's
attempted support for > 137G HDs.
Other threads elsewhere are contending that even Win9x can work on >
137G HDs, as long as all volumes are < 137G and appropriate HD
controller drivers are in effect. This is even more brittle, as
several contexts in Win9x do indeed fall through to BIOS, i.e. Safe
Mode, DOS compatibility mode, and DOS mode itself.
Don't pay malware vendors - boycott Sony
cquirke:
I mean no offense, but I find your comments impenetrable at least with
respect to responding to specific points you have raised. So let me
reiterate my previous statement...
If a user's motherboard's BIOS does *not* support large-capacity disks,
i.e., drives > 137 GB and the user's hard drive is directly connected to the
motherboard, i.e., no HD controller card or drive overlay program is in play
here, then the XP OS, REGARDLESS of whether that OS includes SP1 and/or SP2,
WILL NOT RECOGNIZE THE FULL CAPACITY OF A DRIVE > 137 GB. Period.
Anna
A
Andy
The proof is in the pudding (the results speak for themselves).
I've been using large drives for almost three years with a number of
motherboards having BIOSes that did and did not have the 137 GB
limitation. In no situation did I find that the motherboards with the
137 GB BIOS limitation prevented a properly configured Windows 2000/XP
from accessing the full capacity of the drives.
Another thing you should know is the BIOS code can only run when the
CPU is operating in real mode, while the processor is in protected
mode when Windows is running. The only way Windows could run BIOS code
to access the hard drive is to force the CPU back to real mode,
something that it does not do.
When I first starting using large disks I ran a bunch of tests to
determine how Windows behaved regarding large drives. Some of the
things I found are:
1. Windows 2000 installation: the BIOS (137 GB limitation or not) and
service pack (slipstreamed into the installation CD) are irrelevant.
In all situations, Windows 2000 setup sees only up to 131,000 MB.
2. Windows 2000 in operation: the BIOS is irrelevant; both service
pack 3 or 4 and EnableBigLBA=1 in the registry must be installed. If
either condition is not satisfied, Windows 2000 is limited to 137 GB.
3. Windows XP installation: the BIOS is irrelevant; Setup with
original XP CD is limited to 131,000 MB; setup with XP CD
incorporating SP1 or 2 does not have 137 GB limitation.
4. The BIOS is relevant when Windows is booted. If a 137 GB-limited
BIOS has to access past 137 GB on the disk in order to read the
directory or a file when Windows is being booted, then the boot
process will fail.
One last thing: don't let autochk perform a chkdsk on a partition that
crosses the 137GB boundary if Windows has not been configured to
properly access large drives (this can happen during installation of
Windows).
I've been using large drives for almost three years with a number of
motherboards having BIOSes that did and did not have the 137 GB
limitation. In no situation did I find that the motherboards with the
137 GB BIOS limitation prevented a properly configured Windows 2000/XP
from accessing the full capacity of the drives.
Another thing you should know is the BIOS code can only run when the
CPU is operating in real mode, while the processor is in protected
mode when Windows is running. The only way Windows could run BIOS code
to access the hard drive is to force the CPU back to real mode,
something that it does not do.
When I first starting using large disks I ran a bunch of tests to
determine how Windows behaved regarding large drives. Some of the
things I found are:
1. Windows 2000 installation: the BIOS (137 GB limitation or not) and
service pack (slipstreamed into the installation CD) are irrelevant.
In all situations, Windows 2000 setup sees only up to 131,000 MB.
2. Windows 2000 in operation: the BIOS is irrelevant; both service
pack 3 or 4 and EnableBigLBA=1 in the registry must be installed. If
either condition is not satisfied, Windows 2000 is limited to 137 GB.
3. Windows XP installation: the BIOS is irrelevant; Setup with
original XP CD is limited to 131,000 MB; setup with XP CD
incorporating SP1 or 2 does not have 137 GB limitation.
4. The BIOS is relevant when Windows is booted. If a 137 GB-limited
BIOS has to access past 137 GB on the disk in order to read the
directory or a file when Windows is being booted, then the boot
process will fail.
One last thing: don't let autochk perform a chkdsk on a partition that
crosses the 137GB boundary if Windows has not been configured to
properly access large drives (this can happen during installation of
Windows).
D
DL
I would still be wary of relying on stored data
Andy said:The proof is in the pudding (the results speak for themselves).
I've been using large drives for almost three years with a number of
motherboards having BIOSes that did and did not have the 137 GB
limitation. In no situation did I find that the motherboards with the
137 GB BIOS limitation prevented a properly configured Windows 2000/XP
from accessing the full capacity of the drives.
Another thing you should know is the BIOS code can only run when the
CPU is operating in real mode, while the processor is in protected
mode when Windows is running. The only way Windows could run BIOS code
to access the hard drive is to force the CPU back to real mode,
something that it does not do.
When I first starting using large disks I ran a bunch of tests to
determine how Windows behaved regarding large drives. Some of the
things I found are:
1. Windows 2000 installation: the BIOS (137 GB limitation or not) and
service pack (slipstreamed into the installation CD) are irrelevant.
In all situations, Windows 2000 setup sees only up to 131,000 MB.
2. Windows 2000 in operation: the BIOS is irrelevant; both service
pack 3 or 4 and EnableBigLBA=1 in the registry must be installed. If
either condition is not satisfied, Windows 2000 is limited to 137 GB.
3. Windows XP installation: the BIOS is irrelevant; Setup with
original XP CD is limited to 131,000 MB; setup with XP CD
incorporating SP1 or 2 does not have 137 GB limitation.
4. The BIOS is relevant when Windows is booted. If a 137 GB-limited
BIOS has to access past 137 GB on the disk in order to read the
directory or a file when Windows is being booted, then the boot
process will fail.
One last thing: don't let autochk perform a chkdsk on a partition that
crosses the 137GB boundary if Windows has not been configured to
properly access large drives (this can happen during installation of
Windows).