I believe it's because they're listed numerically. Sandy oc's a little better, more recent cpu's have slightly higher ipc efficiency. Pretty much balances out I think. It would also be hard to rate cpu's based on overclocking since each cpu overclocks a bit differently. In one comparison you could have a sb that was a good overclocker and a d.c. that was a poor one, the next time it could be the other way around.