hes not asking the difference between A1 and T1 but you would be correct if he was,
the mobo in question is the 680i (special edition) engineered for overclocking core 2 duos.
http://www.evga.com/products/pdf/122-CK-NF63.pdf
I called eVGA about this and argued with them because they couldnt give me a straight answer. From what the guy said, it does have quad core support but it wont OC them very well, so I asked him if it was like an old rev 680i that wouldnt hit high fsb without the mod. He replied yes but it will still clock dual cores just fine and has quad core support. Then he contradicted himself buy saying there was no different between this mobo and the A1/T1 and I really couldnt get a answer out of him if infact these are without the gtl mod that made the later A1 and T1 such great quad clockers. I also asked if it was "so specially engineered for overclocking dual core" then whats different between this mobo and the A1/T1 and he couldnt tell me squat. Again from what I figure they havnt or cant perform the gtl mod on these mobos so they release them as somewhat cheaper and advertise them as dual core overclockers that have quad support, that basically wont clock much over 350 with a quad. One of the shadier things eVGA has done in my opinion, but I could be wrong about it all.