LBA, Logical Block Addressing, was created to allow usage of drives past
the old IDE limit, by providing a 28 bit address for blocks.  A hard
drive block is 512 bytes.  28 bits gets us 268 million blocks, or 137
billion bytes (not 1024^3 billion, but 10^9 billion).

The next iteration is 48 bit LBA.  Should allow for 281 trillion blocks,
or 144 quadrillion bytes (10^15).  Of course the HD makers will say 144
PetaBytes, but it will show up on the computer as 128 PetaBytes (1024^5)

Many 'current' operating systems were programmed and released before the
48bit spec was finalized, and well before BIOS updates came out for the
newer drives.  Some drive manufacturers released drives before final
spec and provided their own utilities to overcome BIOS and OS limits.

-Adam

Robert Rolf wrote:

>John Ferrell wrote:
>
>
>>I ordered & received a Seagate 200GB drive from TigerDirect for
>>$149+$11.32+tax-$50 rebate. It was packed in two plastic shells suspended in
>>a pair of foam shock absorbers. Installation was well documented but
>>required a large down load from the Seagate site. It had to make a registry
>>change in XP Pro to get by the 137 GB boundry.
>>
>>
>
>What 137GB boundary? I'm looking at buying a 160GB drive RSN.
>Are we STILL running into stupid software/BIOSes? 512MB, 8GB and now 137GB?
>R
>
>--
>http://www.piclist.com hint: The PICList is archived three different
>ways.  See http://www.piclist.com/#archives for details.
>
>
>
>
>

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.