We wanted to compare the overclocked Core 2 Extreme QX9770 to the best of its predecessors. The "correct" dual-core processor for this task would have been the Core 2 Duo E6850, but our E6750 sample still has all the overclocking capability of the higher-numbered model. The E6750's stock-speed results appear irrelevant, but were included to complete the charts.
Minimal differences in Call of Duty 2 show that some gamers would be better-off spending the extra money required for an "Extreme" processor on other hardware.
F.E.A.R responds well to the Yorkfield's newer core technology, even if it doesn't take advantage of all four cores on either the QX6850 or QX9770. At maximum speed, the QX9770 beats the E6750 by more than its speed difference.
Quake 4 gets a slightly larger boost from the newer core technology, while performance scaling still favors increased clock speed over added cores.