Based on these two Crystal Mark charts we can see that a 1.2 Ghz Celeron 220 (D201GLY2) is almost equal in performance with a 1.6 Ghz Atom processor on the ALU operation. However, the FPU operations are a bit weaker on the Atom. So yes it's true, it's definitely slower than a Celeron, but not as drastic. There's so many Celerons out there, I wonder which he was referring to?