The Extreme Edition Pentium processors support Intel's Hyperthreading feature, which as we have extensively reported in the past, enables a processor core to act as two virtual physical cores. While this helps to increase system responsiveness with single-core Pentium 4 processors, it does not make much of a difference for the double core Extreme Edition.

There are now processors with either one or two processing cores on the market. Processors with two cores (and eventually four and more cores) clearly represent the future, since PC operating systems can share workloads across all available physical cores, which increases performance much more efficiently than any clock speed enhancement could. The performance of thread-optimized applications is also tied to the number of CPU cores. In addition, multiple cores increase system responsiveness: Your machine is less unlikely to not react to mouse or keyboard inputs anymore.

AMD offers the Athlon 64 family and the Athlon 64 X2, which is its dual-core product. Intel has Pentium 4 single-core and Pentium D two-core products. While AMD's dual cores consist of one piece of silicon, Intel puts two single core Pentium 4 processors into its Socket 775 processor package (Pentium D 900 series). Still, each core has its own L2 cache.

AMD's design uses an on-chip processor interconnect, while Intel's device has to utilize the system bus for any inter-core data access. Also, AMD integrates the memory controller with the processor, while Intel follows the classic approach by having the memory controller rely on the motherboard's core logic. The advantages of AMD's integration are shorter memory latencies and thus higher memory efficiency, which is one reason why Athlon 64 processors outperform the Pentium processors in the majority of benchmarks. In addition, AMD's integration approach and the more elaborate manufacturing process (Silicon on Insulator - SOI) lead to clearly better energy efficiency when compared to Intel systems.