Synthetic benchmarks

PCMark Vantage results in points
Intel Core I7-965 Extr. Edition, 3.2 GHz	7'457
Intel Core I7-920, 2.66 GHz	6'655
Intel Core2 Quad Extreme Q9650	6'004
Intel Core2 Dual E8600	5'230
Intel Core2 Dual E7200	4'297
more is better

3DMark Vantage, Performance Preset (CPU Score), results in points
Intel Core I7-965 Extr. Edition, 3.2 GHz	19'837
Intel Core I7-920, 2.66 GHz	17'033
Intel Core2 Quad Extreme Q9650, 3.0 GHz	12'627
Intel Core2 Dual E8600, 3.3 GHz	6'883
Intel Core2 Dual E7200, 2.53 GHz	5'095
more is better

3DMarkVantage not only profits from the overworked architecture it does so also because it is optimized to run in an environment with eight cores. The performance advantage for the Nehalem in this case is 24 percent.

SuperPI 1.5 - 1M
Intel Core I7-965 Extr.Edition 3.2 GHz	12.106 sec
Intel Core2 Dual E8600, 3.3 GHz	13.843 sec
Intel Core I7-920, 2.66 GHz	14.562 sec
Intel Core2 Quad Extreme Q9650, 3.0 GHz	14.390 sec
Intel Core2 Dual E7200, 2.53 GHz	19.905 sec
less is better

SuperPI 1.5 - 32M
IntelCore I7-965 Extr. Edition 3.2 GHz	680.875 sec
Intel Core I7-920, 2.66 GHz	798.552 sec
Intel Core2 Dual E8600, 3.3 GHz	855.047 sec
Intel Core2 Quad Extreme Q9650, 3.0 GHz	912.469 sec
Intel Core2 Dual E7200,2.53 GHz DDR3	1105.000 sec
less is better

In SuperPi 1M Core i7 965 performs about 14 percent better then a Q9650. If one calculates Pi to 32 million digits Nehalem performs 26 percent better.