Well, the overclocked X2 5000+ dominates here. The stock E6600 is handily beaten by the stock X2 5000+ ... the built-in memory controller sure pays off for memory benchmarks.
RightMark Write
The difference is even more evident in writes, with the stock E6600 being on the bottom of the heap, but the overclocked E6600 manages to outwrite the stock X2 5000+ ... but the overclocked X2 is untouchable.