Intel's Pentium 4 Extreme Edition processor (P4 EE) is aimed at the top end of the consumer market, at users who want ultimate performance for serious gaming and multimedia production applications. We looked at a version of the chip with a clock speed of 3.46GHz.

The P4 EE has always been a performance step ahead of the regular Pentium 4 chips due to the total amount of cache memory. A regular Pentium 4 has a 1MB of level 2 cache, while the P4 EE has 512KB of level 2 cache as well as a 2MB level 3 cache. Cache memory is accessible to the CPU much quicker than regular system memory, due to its integration with the CPU itself. It is a place where frequently used data is stored.

In addition to the level 3 cache, the recent P4 EE processors differentiate themselves from regular Pentium 4 chips with improved frontside bus speed. The chip we looked at incorporates a quad-pumped 266MHz frontside bus (FSB) speed of 1066MHz, as opposed to the 800MHz of the regular Pentium 4 chips. The speed of the FSB determines how fast the processor can talk to main memory and other system components.

We used PC WorldBench 5 to compare the speeds of the P4 EE with the AMD Athlon 64 FX-55 and AMD Athlon 64 4000+ in workloads encompassing office applications, design, music and video encoding as well as multitasking. The Athlon FX-55, with its 2.6GHz clock speed, is the clear winner here. It posted a score that is 10% faster than the baseline system score of 100 for this benchmark.

The almost identical Athlon 64 4000+ (2.4GHz), posted a score that is 8% faster than the baseline, while the P4 EE 3.46GHz chip posted a score that is 1% slower than the baseline for this benchmark.

The P4 EE 3.4GHz chip has an advantage in 3DMark 2005, which is based on DirectX 9.0 tests, but the Unreal Tournament frame rate scores are well matched between all the CPUs.

In terms of heat generation, the P4 EE 3.46GHz chip has a thermal power dissipation rating of 110 watts, while the Athlon 64 FX-55 is rated at 104 watts and the Athlon 64 4000+ at 89 watts.

If you're after the best overall application performance for your system, then the single-core Athlon 64 chips will do, but if you're after blazing gaming performance, then the P4 EE 3.46GHz chip has a slight advantage.