Re: What is the difference between x86 and IA32
almost perfect answer. But you are a little bit wrong about the PCI/PCI Express/PCI-X part.
Yes, dumbasses (even some magazines), say 'PCI X' when they mean PCIE.
But PCI-X is not just 'PCI with 64 bit'.
Normal PCI: 32 or 64 bit, 33 or 64MHz (so 32bit/33 is the usual, there is 32/66, 64/33 and 64/66... ).
PCI-X: 64bit, 133 MHz (never 266 MHz).