Even though we got an engineering sample with its clock multiplier unlocked we only played with the external clock, since this is the only option regular users have to overclock their CPU.

First tried to increase the CPU external clock from 266 MHz (“1,066 MHz”) to 333 MHz (“1,333 MHz”) and the CPU worked just fine at an internal clock rate of 3.17 GHz.

From there we started increasing the CPU external clock rate until we got the maximum clock with our system running stable. This was achieved at 353 MHz (“1,412 MHz”), with our CPU running internally at 3.35 GHz. This is an outstanding 32.41% increase on the CPU internal clock rate. Holy cow. At this configuration our memories were running at 1,062 MHz (we were using DDR2-1066 memories) and we locked the PCI Express clock at 100 MHz. Under this overclocking we could achieve 201.92 frames per second on Quake 4 with image quality set to “low.” This represents a 10.31% performance increase on this game.

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Figure 3: Our Core 2 Duo E7200 running at 3.35 GHz.

We honestly hope that the commercial version of Core 2 Duo E7200 also has this same overclocking capability.