What determines the size of a hard drive that can be formated? Is it the BIOS? If so how do I determine what the largest size hard drive my BIOS can support? I'm running Windows XP Pro and have an old Biostar P4M80 M4 motherboard. I wish to add a 1 terrabyte drive.

There are three factors: the HDD itself, the HDD controller on your mobo, and the OS. Over a decade ago they went to using "LBA" for disk addressing. At that time they used 28-bit addressing for LBA, which allows for a maximum size to 138 Billion bytes (or, M$ Windows calls that 127 GB).

Around 2000 that system was upgraded to "48-bit LBA Support", which allows for HDD's up into the petabyte region! All three components of the system need to support 48-bit LBA for this to work. Whether or not your mobo's HDD controller has this should be available from your mobo manufacturer's website. Look for statements about "48-bit LBA" or HDD's over 127 GB. Just plain "LBA" or "Large hard drive" is not clear enough. WARNING: If you try to use an OS that allows larger drives when the HDD controller does not, you could corrupt your drive. Basically in some situations the OS may try to write to an area above 127 GB, but the controller will fail to pass on the full address, and the write operation will happen near the start of the drive, corrupting what's there.

As another clue, ALL SATA drive systems (controllers and HDD's) support 48-bit LBA - the new system was in place when SATA was introduced, and it was built into the SATA designs. So in your case if you are installing a SATA drive, for sure the HDD and its controller will be OK.

On the OS side, it also needs to support 48-bit LBA. Windows 2000 did not until a later Service Pack (I think 4, but I'm not sure). Win XP originally did not; it was added with SP1 and continued thereafter. If you don't have SP2 installed (or at very least SP1), download and install now.

Technically, 127 GB is correct, as the binary basis for determining kilo / mega / giga / etc. is the norm in computing (KB = 1,024 B). The decimal system is only used by the HD manufacturers because it allows them to advertise higher capacities. It's a marketing gimmic. So don't blame MS for that.

"Whether or not your mobo's HDD controller has this should be available from your mobo manufacturer's website."

It's an old motherboard... Biostar P4M80 M4 and I can't find much info about it on Biostar's website .

Both my hard drives are running SATA 1 and both plug into the Biostar P4M80 M4 motherboard. The Biostar P4M80 M4 motherboard only supports SATA 1. Does this mean I can format a 1 terabyte drive under Windows XP Pro running Service Pack 3 and use it with this motherboard? If I read what you wrote above correctly the answer is yes.

I take it there is no way for me to upgrade to SATA II without changing the motherboard which I would rather not do?

With an older board like you have sata 1 will be fine, that said you can add a sata 2 controller if you wish for about $30.

I can buy a SATA 2 controller that plugs into one of my PCI slots and get all the benefits of SATA 2 with no drawbacks? Sounds to good to be true. I take it the SATA 2 controller card has it's own BIOS and will by-pass the SATA 1 controller that my motherboard currently has?

There currently is no benefit to SATA 3Gbit/sec. (SATA 2) over SATA 150Gbit/sec. (SATA1). Don't waste your money.

By using a SATA contoller card in a PCI slot, you will be limited by the amount of data that a PCI bus can handle.
Which is already a lot less than what SATA/300 can handle.
Add to that problem if you're going to be using multiple drives attached to the new SATA card.
It will definitley work, but you will have (potentially) slower hard drives because of the PCI slot.

Yeah, that and the fact that SATA 2 is complete BS. The fastest conventional HD isn't even saturating SATA 1 yet. Not counting the buffer, which is too small to make a real difference.

"By using a SATA contoller card in a PCI slot, you will be limited by the amount of data that a PCI bus can handle. Which is already a lot less than what SATA/300 can handle."

That makes sense to me.

Does everyone agree that I won't have a problem formating a 1 terabyte drive with the motherboard I have that only supports SATA 1?

I'd like to buy the new 1 terabyte drive and install it today.

"Yeah, that and the fact that SATA 2 is complete BS. The fastest conventional HD isn't even saturating SATA 1 yet. Not counting the buffer, which is too small to make a real difference."

Interesting. Do you have any links to support this? Thanks in advance.

All you have to do is look at the read/write throughput performance on the 3.5" Hard Drive Charts. Interface speed doesn't mean squat unless the physical properties of the drive can deliver the bandwidth, which they can't yet. Again, barring the buffer which is still so small that it has little real affect. Some yes, just not a lot. PATA isn't even saturated by the drives out there, the fastest are getting real close though.

Very helpful. Thank you.

Since they are both SATA drives connected to mobo sockets, you have no problem. I understand ALL SATA drives support 48-bit LBA, and so do SATA controllers. XP Pro with SP3 also will do all you need. Go ahead.

Switching to SATA II is not worth it for you. The general finding is that almost no drives actually come close to the SATA I maximum throughput spec, and SATA II is a spec waiting for the hardware to catch up to it. Do not waste money replacing your mobo or buying / installing a PCI SATA II controller board. However, when you buy your HDD it's almost impossible to get anything other than SATA II, and that's OK. Most will arrive with a little jumper installed on a pair of pins - the only jumper a SATA drive needs. As installed, it limits the drive to SATA I performance to ensure it's fully compatible with older SATA I controllers (your case), so leave it on. Removing it makes it run as SATA II for those with newer controllers.

You should be just fine, Zorg knows his stuff !