48Bit LBA Question

[Jim Stuart]

I have an older PC running Windows XP SP2 that does not support 48Bit LBA. I
would like to install a 160GB hard drive as a replacement for two smaller
drives.

If I create a primary partition (15GB) for the OS and an extended partition
containing a number of logical partitions non of which are greater than 30GB
will I run into any problems? I plan to move the existing OS over to the new
drive using Ghost.

Jim

 

[Andy]

I have an older PC running Windows XP SP2 that does not support 48Bit LBA. I
would like to install a 160GB hard drive as a replacement for two smaller
drives.

If I create a primary partition (15GB) for the OS and an extended partition
containing a number of logical partitions non of which are greater than 30GB
will I run into any problems? I plan to move the existing OS over to the new
drive using Ghost.

Jim

You shouldn't have any problems as long as you things the right way.

 

[Snarky Parker]

You will still be limited to whatever the BIOS will allow (137GB or less).

Don't let the mfg's drive utility install a DDO to allow full access.

Keep this in mind also, drive manufacturers measure their products using decimel
rather than the binary system. Your drive, if fully formatted in a system that
supports 48bit LBA and with the proper registry setting, will be reported as
"160,000,000,000 bytes 149 GB" in Windows properties.

Read this FAQ for details:

Why is my drive displaying a smaller than expected capacity than the indicated
size on the drive label?
http://wdc.custhelp.com/cgi-bin/wdc...3B2PSZwX2N2PSZwX3BhZ2U9MQ**&p_li=&p_topview=1


| I have an older PC running Windows XP SP2 that does not support 48Bit LBA. I
| would like to install a 160GB hard drive as a replacement for two smaller
| drives.
|
| If I create a primary partition (15GB) for the OS and an extended partition
| containing a number of logical partitions non of which are greater than 30GB
| will I run into any problems? I plan to move the existing OS over to the new
| drive using Ghost.
|
| Jim
|
|

 

[Jim Stuart]

So as I understand it, it's not 137GB per partition but the total of all
partitions (Primary and Logical) can not exceed 137GB for any hard drive
connected to my PC.

Jim

 

[Snarky Parker]

That would be correct if you use the NTFS format. See this article for
limitations when using FAT32:

Limitations of the FAT32 File System in Windows XP
http://support.microsoft.com/kb/314463/EN-US/

| So as I understand it, it's not 137GB per partition but the total of all
| partitions (Primary and Logical) can not exceed 137GB for any hard drive
| connected to my PC.
|
| Jim
|
|
| | >I have an older PC running Windows XP SP2 that does not support 48Bit LBA.
| >I would like to install a 160GB hard drive as a replacement for two smaller
| >drives.
| >
| > If I create a primary partition (15GB) for the OS and an extended
| > partition containing a number of logical partitions non of which are
| > greater than 30GB will I run into any problems? I plan to move the
| > existing OS over to the new drive using Ghost.
| >
| > Jim
| >
|
|

 

[John R Weiss]

So as I understand it, it's not 137GB per partition but the total of all
partitions (Primary and Logical) can not exceed 137GB for any hard drive
connected to my PC.

Correct.

I just tried to partition & format a 300 GB HD in my USB external enclosure
(which doesn't support 48-bit LBA). Not only would it only go to the 137 GB
total, but access was significantly slower than the old HD.

I took it out of the enclosure and repartitioned/reformatted it using a
temporary internal IDE connection. That was successful, and performance is now
back to what I expected.

Now I have a new external enclosure on order to support the big HD...

 

[Jim Stuart]

Thanks for everyone's help.

Jim

 

[Jonny]

You failed to see the limtitation in your case. It was the enclosure's USB
bios for IDE capacity, not anything else.

 

[John R Weiss]

Not quite...

I recognized the enclosure's limitation when I first tried to partition the HD.
However, the key portion is that the HD performance was considerably degraded
after partitioning and formatting it within that limitation.

After that experience, I would not recommend anyone try to use a larger capacity
HD, formatted for the lower capacity in systems that don't support 48-bit LBA.