Not quite true, if the motherboard is old enough (2002 or earlier) it will run into the 137GB hard drive limit because it lacks 48-bit LBA addressing
. Also, the OS must support it (WinXP SP1 and above if I remember right.)
Just want to make that clear in case someone browsing the forums runs across this thread.
Your D946GXIS supports 48-bit LBA so you should be able to use a 1TB hard drive (assuming your OS supports it).