I'm getting close to that on my intel i5 on beeeeer.org - might be worth seeing if you have better results?
http://beeeeer.org/You mine the same amount of XPM/day on one i5 CPU as he's mining on 18 cores?
Ypool kinda sucks...imho.
I get 3.5xpm per day on my i7 3820 at 4.3ghz.