48Bit LBA Question

  • Thread starter Thread starter Jim Stuart
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J

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
 
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
Click to expand...
You shouldn't have any problems as long as you things the right way.
 
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
|
|
 
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
 
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
| >
|
|
 
Jim Stuart said:
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.
Click to expand...

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