Product Reviews

The Pentium 4 is Intel's latest flagship consumer processor, and the first Intel chip to use an entirely new architecture since its Pentium Pro was released, way back in 1995. The most important feature of the new design is the lengthening of the 'pipeline' inside the processor. The pipeline is the set of stages an instruction goes through before it is executed. Lengthening the pipeline means that each instruction takes longer to complete because it's done in many more stages. However, because each stage is simpler, this allows you to push the clock speed higher. When the processor reaches a high enough clock speed, this compensates for the loss of performance caused by the longer pipeline. And this is why the Pentium 4 is getting much more competitive as its clock speed is cranked up past the break-even point. Earlier, slower, Pentium 4s compared badly with the fastest Athlons at that time. Current Pentium 4 processors do much better against the latest crop of Athlon XPs.

Will it work in my PC?

Unless you bought your PC very recently, almost certainly not. From 1.3GHz to 1.5GHz, Pentium 4 processors came in Socket 423 shape, so called because it has 423 pins.

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Pentium 4s rated at between 1.5 to 2GHz are available in both Socket 423 and the new Socket 478 style, which is smaller despite having 55 extra pins. Above 2GHz there will only be Socket 478.

So if you have an old Socket 370 Pentium III motherboard, none of these processors will fit in your PC. Likewise if you've got an old Socket 423 Pentium 4, you won't be able to upgrade to more than 2GHz. And if you decide to upgrade from a slower Pentium 4 to one of the faster models, make sure you get the version that will fit in your machine.

Performance

Apart form its longer pipeline, the other defining feature of the Pentium 4's architecture is its super-fast front-side bus, which runs at 400MHz. This is great, if you have the right memory. With either RDRAM or DDRAM, the Pentium 4 achieves speeds that rival those of the Athlon XP. Give it slower SDRAM, however, and the Pentium 4's performance is throttled because SDRAM only runs at 133MHz.

In fact, its performance is so bad with SDRAM, that if you're not going to invest in either DDR or RDRAM, you'd be better sticking with a Pentium III or Celeron!

Overall

Given the right memory, the Pentium 4 performs really well. Until recently, the 'right' memory to use with it was RDRAM, which cost up to twice as much as other memory types.

The good news is that VIA, SiS and Intel have now all brought out motherboard chipsets for the Pentium 4 that support DDR RAM - twice as fast as normal SDRAM, but not much more expensive. The 1.9GHz Pentium 4 is also due to come down in price soon, so ring Simply for the latest. So overall, a decent choice for a new PC, and potentially a reasonable one for future upgraders if Intel stops messing about with the socket shape and memory support.