My friend has a 2 p3 1Gmhz pc,a cool pc,

My pc's cpu is celeron3 1.3Gmhz,and I run a test,to render a maya file.
My total render time is 1'25''
double p3's time is 1'33''!!!!

As I known in maya render, 2 cpu is better than 1,and p3 1g performance is close to c3 1.3g,why my c1.3 is faster than double p3 1g?

I use w2k,and my friend is xp.