Partition Magic can't see XP's partitions

[Mark M]

I am running XP Pro + SP1. My BIOS supports hard drives only up to
137 MB.

Using XP's Disk Management I created several partitions on a 160 GB
hard drive (132 GB, 8 MB, 8 GB, 19 GB and 15 GB unallocated).

All seem to work alright.

For some reason Partition Magic 8 can not see any partitions on that
hard drive and it says the whole drive is "bad".

I feel pretty certain that PM8 was previously able to show me the
partitions on this 160 GB hard drive until I deleted them and re-
created another set of partitions.

Is it important or significant that PM8 currently can't see any of
the partitions?

 

[Ron Sommer]

Adding the partitions gets 182.

 

[Mark M]

Adding the partitions gets 182.

Actually it sums to 174. That "8 Mb" I wrote was not a typo.

WinXP's Disk Management reports the disk as having 173.46 GB
capacity.

160 GB x 1.07377 = 171.8. [1 binary GB = 1.07377 decimal GB.]

Seems to me that Samsung rate their hard drives in binary GB.

 

[Rod Speed]

Cant say I have bothered to use it on an XP prepared drive.

When I do want to do some minor adjustments
to partition sizes I just use Drive Image 2002.

Nope, likely just some stuffup in PM8

Actually it sums to 174. That "8 Mb" I wrote was not a typo.

WinXP's Disk Management reports
the disk as having 173.46 GB capacity.

160 GB x 1.07377 = 171.8. [1 binary GB = 1.07377 decimal GB.]

Seems to me that Samsung rate their hard drives in binary GB.

Nope. Certainly doesnt with my 120GB Samsung drive.

XP shows the total capacity of the 3 FAT32 partitions
as 111.6GB in My Computer. And the physical drive
as 114495 MB in the propertys of that drive.

 

[Mark M]

Cant say I have bothered to use it on an XP prepared drive.

When I do want to do some minor adjustments
to partition sizes I just use Drive Image 2002.

Nope, likely just some stuffup in PM8

Actually it sums to 174. That "8 Mb" I wrote was not a typo.

WinXP's Disk Management reports the disk as having 173.46 GB
capacity.

160 GB x 1.07377 = 171.8. [1 binary GB = 1.07377 decimal GB.]

Seems to me that Samsung rate their hard drives in binary GB.

Nope. Certainly doesnt with my 120GB Samsung drive.

XP shows the total capacity of the 3 FAT32 partitions
as 111.6GB in My Computer. And the physical drive
as 114495 MB in the propertys of that drive.

Using XP's Disk Management tool, I see these results on the same
display:

Seagate Barracuda 60 GB comes up as 55.90 GB
Seagate Barracuda 120 GB comes up as 111.79 GB
old Samsung 20GB comes up as 19.01 GB
Samsung 160 GB comes up as 173.46 GB.

Maybe it's a glitch in XP but as I calculated above, the difference
for the 160 GB drive is almost exactly the difference between decimal
and binary GB.

However, the strange thing is that those "smaller than specified"
values for the other three hard drives are presumably beig shown in
*binary* GB. Whereas the "larger than specified" value for the 160
GB Samsung is presumably in *decimal* GB.

 

[Mark M]

If the Bios can't see all of the drive, then XP shouldn't be
able to see it either.

Ron, I think that if you have XP + SP1 then even if your BIOS is not
capable of 48 bit addressing, you can still see above 127 GB.

Have a look at the subthread starting with my posting. Ignore the
banter.


From: Mark M <[email protected]>
Newsgroups: comp.sys.ibm.pc.hardware.storage
Subject: Re: Installing a DDO... HOW!?! Please help
Date: Thu, 23 Oct 2003 08:57:34 +0100
Message-ID: <news:[email protected]>

 

[Rod Speed]

Cant say I have bothered to use it on an XP prepared drive.

When I do want to do some minor adjustments
to partition sizes I just use Drive Image 2002.

I feel pretty certain that PM8 was previously able to
show me the partitions on this 160 GB hard drive until
I deleted them and re- created another set of partitions.

Is it important or significant that PM8 currently can't see
any of the partitions?

Nope, likely just some stuffup in PM8

Ron Sommer <[email protected]> wrote

Adding the partitions gets 182.

Actually it sums to 174. That "8 Mb" I wrote was not a typo.

WinXP's Disk Management reports the disk as having 173.46 GB
capacity.

160 GB x 1.07377 = 171.8. [1 binary GB = 1.07377 decimal GB.]

Seems to me that Samsung rate their hard drives in binary GB.

Nope. Certainly doesnt with my 120GB Samsung drive.

XP shows the total capacity of the 3 FAT32 partitions
as 111.6GB in My Computer. And the physical drive
as 114495 MB in the propertys of that drive.

Using XP's Disk Management tool, I see these results on the same
display:

Seagate Barracuda 60 GB comes up as 55.90 GB
Seagate Barracuda 120 GB comes up as 111.79 GB
old Samsung 20GB comes up as 19.01 GB
Samsung 160 GB comes up as 173.46 GB.

Maybe it's a glitch in XP

Yeah, most likely. Likely its no coincidence that that drive is over 128GB.

but as I calculated above, the difference for the 160 GB drive
is almost exactly the difference between decimal and binary GB.

Yeah, but you can see from the Samsung web site
that they do use decimal GBs just like everyone else.

Very explicit on the bottom of
http://www.samsung.com/Products/Har...es/HardDiskDrive_SpinPointPSeries_SP1614N.htm

However, the strange thing is that those "smaller than specified" values
for the other three hard drives are presumably beig shown in *binary* GB.
Yep.

Whereas the "larger than specified" value for the
160 GB Samsung is presumably in *decimal* GB.

Nope. Samsung says that drive is 160GB using decimal GBs.
There must be some other reason for the size XP states.

 

[Mark M]

Yeah, most likely. Likely its no coincidence that that drive is
over 128GB.

And there I was thinking that XP + SP1 was able to properly handle
hard drives over 128 GB without BIOS support. Guess XP must still
have glitches when it tries to do this.

Yeah, but you can see from the Samsung web site
that they do use decimal GBs just like everyone else.

Very explicit on the bottom of
http://www.samsung.com/Products/HardDiskDrive/SpinPointPSeries/Ha
rdDiskDrive_SpinPointPSeries_SP1614N.htm

Very true.

Yep.

That is a bit worrying for me because I don't want to find there is
some another (perhaps unannounced or currently unknown) glitch in XP
which screws up the partition boundaries on that hard drive on
account of XP doing some miscounting somewhere.

Maybe what I should do is partition this 160 GB drive with a 128 GB
partition (just to be safe) and then have the remainder just used for
non-critical data

Nope. Samsung says that drive is 160GB using decimal GBs.
There must be some other reason for the size XP states.

I can't be the first person to hit this so I guess that somewhere it
must be known.

To be fair to Microsoft they do say explicitly in their article
http://support.microsoft.com/default.aspx?scid=kb;en-us;303013 that a
48 bit BIOS is necessary.

Folkert seemed to believe (see ref below) that 48 bit BIOS support is
not really necessary despite Microsoft's words in that document. In
a sense he is right because it seems my XP can access all the 160 GB
without a 48 bit BIOS. But maybe XP needs the 48 bit BIOS support
for other drive support functions such as displaying decimal/binary
values correctly. I guess its possible that these other functions
might turn out to be important.

Maybe I should ask Samsung direct.

 

[Ron Sommer]

And there I was thinking that XP + SP1 was able to properly handle
hard drives over 128 GB without BIOS support. Guess XP must still
have glitches when it tries to do this.



Very true.


That is a bit worrying for me because I don't want to find there is
some another (perhaps unannounced or currently unknown) glitch in XP
which screws up the partition boundaries on that hard drive on
account of XP doing some miscounting somewhere.

Maybe what I should do is partition this 160 GB drive with a 128 GB
partition (just to be safe) and then have the remainder just used for
non-critical data

If the Bios doesn't support the 160GB drive, then you won't have a remainder
to work with.

 

[Mark M]

If the Bios doesn't support the 160GB drive, then you won't have
a remainder to work with.

Ecen though my BIOS does not have 48-bit support my copy of XP (XP
Pro + SP1) seems to allow me to partition and use the whole of the
160 GB.

 

[Rod Speed]

And there I was thinking that XP + SP1 was able to properly
handle hard drives over 128 GB without BIOS support.

The MSKB article says very explicitly indeed that
you need BOTH the SP and support in the bios.

Guess XP must still have glitches when it tries to do this.

Or that MS never claimed it would work
without bios support for those drives.

Maybe its just cosmetic too in the sense
that its the reported size thats wrong.

Very true.

That is a bit worrying for me because I don't want to find there
is some another (perhaps unannounced or currently unknown)
glitch in XP which screws up the partition boundaries on that
hard drive on account of XP doing some miscounting somewhere.

Yeah, but you've always been a worrier |-)

Maybe what I should do is partition this 160 GB
drive with a 128 GB partition (just to be safe) and
then have the remainder just used for non-critical data

I'm not convinced that that would guarantee no problem is possible.

I can't be the first person to hit this so I
guess that somewhere it must be known.

Very likely. Tho most may well just ensure that the bios is 48 bit capable.

To be fair to Microsoft they do say explicitly in their article
http://support.microsoft.com/default.aspx?scid=kb;en-us;303013
that a 48 bit BIOS is necessary.
Precisely.

Folkert seemed to believe (see ref below) that 48 bit BIOS support
is not really necessary despite Microsoft's words in that document.

Yeah, but that fool is so stupid that he cant even manage to
work out that read ahead at the OS level wont necessarily
be reading contiguous sectors at the platter level of the drive.

In a sense he is right because it seems my XP can access
all the 160 GB without a 48 bit BIOS. But maybe XP needs
the 48 bit BIOS support for other drive support functions
such as displaying decimal/binary values correctly.

Yep, there have been a few examples where MS OS
components have had significant brain farts at particular
boundarys when reporting drive capacity. Most obviously with
fdisk reporting the size over 64GB with drives bigger than that.

I guess its possible that these other
functions might turn out to be important.
Maybe.

Maybe I should ask Samsung direct.

Nothing to do with Samsung.

 

[Rod Speed]

If the Bios doesn't support the 160GB drive,
then you won't have a remainder to work with.

He clearly does tho.