Sorry, so the Tegra is call X2 and the DMP M3000 is called PICA 200? Sooooo Tegra X2 (kid buu) vs PICA 200 (SS3 Goku). Did I get that right?
Okay, let me make is simple.
Tegra 2 = Very old Tegra which was considered for 3DS
PICA 200 = The GPU which actually ended up in 3DS
Tegra X2 = Unofficial name for the new Tegra (official name is Parker, at least for now)
DMP M3000 = A new GPU from the same people who made the 3DS GPU
Tegra Parker is faster than M3000, we think. It's a but of a guess at this point though.