South bridge and north bridge. They're the board controllers, basically. North bridge takes care of the buses/voltage/clocks ETC and the south takes care of the SATA, ETC.
Now the north bridges are identical. IE - they're both X58. An Intel north bridge. Look over the other specs (PCIE lane speeds, slots, sata sockets) ETC and see if they are the same.
Asus don't make north/south bridge chips (AKA the chipset) they rely on others. Sooo, I could be right and they could have just slapped on nicer looking coolers (for the north and south bridges) and charge more for the name (ROG).
The P6T is one of the best motherboards *ever* made dude. It's absolutely sublime.
Rampage 2 E.
Chipset - Intel X58/ICH10R (X58 northbridge Intel ICH10R southbridge)
Pic.
Asus P6T deluxe/professional ETC
Chipset: Intel® X58 / ICH10R. So as I suspected, the same.
Pic.
Do your homework on the PCIE slots, but it's basically the same board. If it works out cheaper? get it.
**Refer to
www.asus.com. Or user manual for the Memory QVL (Qualified Vendor Lists.)
Expansion Slots
: 3 x PCIe 2.0 x16 (at x16/x16/x1 or x16/x8/x8 mode)
1 x PCIe x4
2 x PCI
So you're going SLI right? then it's more than good enough for your needs. What do they cost over there?