The above synthetic SiSoft XI processor and multimedia tests measure the full performance of dual-core and quad-core processors. The scores are pretty much four times greater on the QX6850 when compared to the X6800. While these kind of gains will not be seen in real-world applications, it does demonstrate the potential power of these quad-core processors.
Super PI doesn't take multi-core into consideration and for that reason a quad-core Intel processor or a dual-core Intel processor will deliver almost the same performance when clocked at the same frequency.
The PCmark2005 results are again shaped more by core clock speed than anything else. The Core 2 Extreme QX6850 is notably faster than the QX6700, while it is only slightly faster than the X6800.