Because Intel's gate oxides had already reached the limits of insulating materials at two molecular layers thick, the company needed a new semiconductor with similar insulating properties but better conductive properties. The new material would be applied at increased thickness, but without the voltage losses that occurred with silicon dioxide gate oxides. After five years of development, Intel was ready to move forward with a molecular structure containing Hafnium. The following images are provided in Intel's press kits.

The use of its new gate oxide allowed Intel to make the remaining components smaller using a 45nm die process, while keeping leakage currents at a minimum. At the same time, Intel also changed its gate conductor from Nickel Silicon to an unspecified metal, to reduce resistance at the part of the gate that doesn't "switch" from insulator to conductor.

The new 45nm process allowed a smaller processor die for increased parts per wafer (reduced cost), while the combination of a smaller transistors and better gate materials provided increased speed. Intel didn't stop there, as the company also added more Level 2 cache, increasing its Core 2 Duo from the 4MB found in the Conroe core to 6MB for the new Wolfdale.

Further enhancements include the addition of its new SSE4 (Streaming SIMD Extensions version 4). SIMD stands for Single Instruction, Multiple Data, and reduces the number of instructions needed to complete a defined set of common tasks.

The current line of Core 2 Duo E8000 series "Wolfdale" processors includes the 2.66GHz E8200, 3.00GHz E8400, and 3.13GHz E8500. The odd-numbered E8500 uses a 9.5X CPU core to FSB multiplier, and we expect this trend to continue for future odd-numbered E8000 series parts. The current naming scheme leaves room for models up to a possible "E8900" at 3.70GHz.

While the lowest-rated model E8200 might be a better value to overclockers, review samples are limited to the highest current model. Intel sent its Core 2 Duo E8500 for our evaluation, which we'll test at both E8200 and E8500 speeds.