windows displays incorrect disk sizes

[janimal666]

pentium4 2.4ghz
abit sa7 motherboard 533mhz bus
disks: 40gb(ok), maxtor.160Gb(shown as 128Gb), west.dig.200Gb(shown as 128Gb)

the sizes of all the above disks are displayed correctly in bios, but winxp (disk management) and partition magic only see 128Gb space on each of the large disks. the 160Gb disk has been low level formatted and the 200Gb disk is factory fresh. any suggestions?

 

[Freestone]

Sounds like a 48-bit LBA issue. Windows XP must be at least at Service Pack 1 level.

For more info see

http://www.48bitlba.com/winxp.htm

 

[stuke]

I have a similar problem. I have Maxtor drives. XP Pro SP2. I even put on the big_drive_enabler.exe from Maxtors web site, but the drives still appear as 32GB, and I can not access the data!

Does anyone know of some usefull tool that sorts it all out???

 

[Freestone]

stuke - normally it's not a good idea to mix threads, but I suggest you browse

http://www.48bitlba.com

and see if any help is there. If no joy, create a new thread so we can keep answers to janimal666 and you separated.

 

[janimal666]

it does sound like stuke has a similar problem. i'm running xpsp2 as well. i've checked the link and though it sounds kinda feasible, i am running the service pack, and the 128Gb ceiling my drives are hitting is lower than the 137Gb they quote on the page. i've double checked, and the drive sizes are definetely shown correctly under cmos, so its not a bios issue, is it? interestingly, the 160Gb disk was being fully recognised for the past few months until i had to get into some data recovery with it and low levelled it, and that was under the same windows configuration i'm running now. i did try to manually enter the disk size when allocating space under disk management and/or partition magic but it made my computer very unhappy and carshed the system.

 

[stuke]

I think that at some point I may have ran checkdisk (on at least one of my drives) to see if there was a simple problem - system error or bad sector problem. After reading some recovery blurb, I am wondering if that may have actually done more harm than good? Perhaps windows fixed my drives good and propper in a Microsoft Feature sort of way!

Have you (janimal666) ran checkdisk too? If so we may have done something similar that resulted in the similar problems we are having.

 

[Freestone]

janimal666: Was sp2 incorporated in your CD or was the service pack applied after the initial XP install?

Does the registry entry described in the below KB article appear in your PC's registry?

http://support.microsoft.com/default.aspx?scid=kb;en-us;303013

 

[janimal666]

i haven't run checkdisk on either drive because it didn't seem like a problem with the drive itself. the service pack was installed immediately after xp install. i can find the registry folder the article mentions but can't see the EnableBigLba entry. i've checked the atapi.sys file version and it's 5.1.2600.2096, later than the 5.1.2600.1135 the article quotes. the sysprep tool stuff went straight over my head.

 

[janimal666]

i ran the maxtor big drive enabler, which is supposed to turn on 48-bit LBA, and updated my bios. according to the abit site my board supports 160Gb as standard and over 160Gb with bios update. i'm still hitting a ceiling of 128Gb depending on where i look at the disk sizes.

 

[janimal666]

disk size shown as 128 or 137.

 

[Freestone]

I wonder if reapplication of Service Pack 2 would help?

 

[janimal666]

alas, no.

 

[Freestone]

I'm still convinced this is an 48-bit LBA issue.

Perhaps we should isolate this to your Windows install. You can examine drive sizes via the free version of KillDisk available at

http://www.killdisk.com/.

I just used the bootable floppy version and it shows my ATA 250GB drive and my SATA 300GB drive sizes correctly. This would definitely confirm BIOS support (though I suspect you have it).

There is also Knoppix and Bart PE I guess that could be used, but the KillDisk method was quickest for me.

Be careful using KillDisk. It is hard to accidentally erase partitions and/or disks with it, but just be aware that erasing is the true function of the program.

 

[Freestone]

I ran across this 48-bit LBA BIOS check utility, and though it is from Intel, it ran okay on my nVIDIA nForce 2 chipset board. Perhaps it'll run on your SiS chipset based board too.

http://www.intel.com/support/chipsets/iaa/sb/cs-009302.htm

I added the utility to a Windows ME boot diskette created from

http://www.bootdisk.com

 

[stuke]

I did a 48bit LBA test too, but I think that it just looks to see if XP SP2 is installed rather than the way it was installed.

 

[janimal666]

i ran the 48lba test and it came up positive. i also ran killdisk and these are the values it gave me:

w d (should be 200Gb)
mobile lba yes
cylinders 387621
tracks per cylinder 16
sectors per track 63
total sectors 390721968
bytes per sector 512
total size 186Gb (200049647616bytes)
127Gb allocated
58.3 Gb unallocated

maxtor (should be 160Gb)
mobile lba yes
cylinders 317632
tracks per cylinder 16
sectors per track 63
total sectors 320173057
bytes per sector 512
total size 152Gb (163928604672bytes)
127Gb allocated
24 Gb unallocated

although that still leaves me short by 14 and 8GB respectively (maybe i'm missing some maths there?), it seemed a step in the right direction, although under cmos the full sizes are shown. i had a look in windows setup; it showed the limited partition sizes, and of course it only gives you the option to format, not to resize a partition. it seems i run into the limit as soon as i enter the windows environment, while everything in dos says all is hunky dory. is it possible to run partition magic or something similar in dos mode to resize the partitions to include any unallocated space and then hope that windows will play ball after restart?

 

[temporello]

Drive manufacturers give different numbers than they should.
In their book 1 GB equals 1000*1000*1000 bytes and not 1024*1024*1024 bytes!
200 GB = 200.000.000.000 bytes,and that would be 186 GB in "normal" IT terms...
And it goes for the other drive as well of courseÉ
160 GB = 160.000.000.000 bytes - in reality 152 GB.

 

[janimal666]

aaaahh... thats good to know.

 

[Freestone]

As temporello says, manufacturers use base 10 math when stating drive sizes, whereas computers work in binary. 1GB equals 1024 * 1024 * 1024 (1,073,741,824), and when you divide the numbers given by killdisk, you will get the same GB sizes as it calculated. Your drive sizes are correct and are not short.

Did you create the partitions on both big drives prior to the install of Service Pack 2? If so, that explains why they were limited to 128GB. Once SP2 is installed, you should be able to use Partition Magic to resize the partitions to their full capacity.

Does Disk Management now show the correct drive sizes? If not, then something is amiss with your XP installation and you may want to consider slipstreaming SP2 onto XP and doing a reinstall. See

http://www.theeldergeek.com/slipstreamed_xpsp2_cd.htm

 

[janimal666]

both large disks were formatted after xpsp. disk manager still quotes 128Gb, although the registry says 48lba is enabled. both the large disks contain duplicate data at the moment, so i guess as a next step i could reformat on of them in partition magic and see how much space it lets me have. is there something that will let me resize the partitions in dos in the hope that windows will then pick the drive size up correctly?