Mixing LBA28 and LBA48 on a single PATA channel

[Tom Anderson]

Hi,

Is it possible to mix 28- and 48-bit LBA on a single ATA channel?

I have a machine with two channels; one carries a pair of CD drives, and
the other currently has an 80 GB hard drive. I haven't enabled LBA48 in
the OS, so i assume everything is using LBA28. I'd like to add a second
hard drive of 160 GB or bigger; the only place for it is on the channel
currently carrying the first drive, and since the drive will be

128 GB, it'll have to use LBA48.

Will that work? Will the machine just use LBA48 for the big disk and keep
talking to the small one in LBA28? Or will it try to talk to the small
disk in LBA48? Will that work? Any ideas?

I actually have two machines in this situation; if their precise specs
matter, they are:

Dell OptiPlex GX270
Chipset: i685G
Drive: 80 GB Western Digital Caviar (WD800BB)
OS: Windows 2000 SP3
BIOS revision: A01

Dell Dimension 8200
Chipset: i850E
Drive: 80 GB Seagate Barracuda ATA IV (ST380021A)
OS: Windows XP SP2
BIOS revision: A03

I should probably update the OSes and BIOSes, but as they stand, i think
the software side is all LBA48-capable.

tom

 

[Rod Speed]

Is it possible to mix 28- and 48-bit LBA on a single ATA channel?

Yep, that's fine.

I have a machine with two channels; one carries a pair of CD drives,
and the other currently has an 80 GB hard drive. I haven't enabled
LBA48 in the OS, so i assume everything is using LBA28. I'd like to
add a second hard drive of 160 GB or bigger; the only place for it is
on the channel currently carrying the first drive, and since the
drive will be > 128 GB, it'll have to use LBA48.

Will that work?

Yes. I'm doing it on one PC, works fine. This one in fact.

Will the machine just use LBA48 for the big disk and keep talking to the small
one in LBA28?

There is no real distinction at that level of commands over the cable.

Or will it try to talk to the small disk in LBA48? Will that work? Any ideas?

It works fine.

I actually have two machines in this situation; if their precise specs matter,
they are:

Dell OptiPlex GX270
Chipset: i685G
Drive: 80 GB Western Digital Caviar (WD800BB)
OS: Windows 2000 SP3
BIOS revision: A01

Dell Dimension 8200
Chipset: i850E
Drive: 80 GB Seagate Barracuda ATA IV (ST380021A)
OS: Windows XP SP2
BIOS revision: A03

I should probably update the OSes and BIOSes, but as they stand, i think the
software side is all LBA48-capable.

It'll work fine as long as 48 bit LBA works.

 

[Tom Anderson]

Yep, that's fine.



Yes. I'm doing it on one PC, works fine. This one in fact.


There is no real distinction at that level of commands over the cable.


It works fine.





It'll work fine as long as 48 bit LBA works.

So, what you're saying is, you think it might work fine?



Thanks very much for the info, Rod!

tom