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Introduction:::...

To those of us a step removed from the "nuts and bolts" end of the industry, it can often be frustrating that what seems like the simplest of ideas can take so long to make it to market.

Without a working knowledge of the intricacies, the constraints and limitations that hinder the boffins who lurk at the bleeding edge of technology, we can't even begin to guess at the complications often involved in bringing even the most obvious of ideas to fruition. If more memory is better why can't we all have 30GB of memory in our machines? If more storage space is better why not just make Terabyte sized hard drives? If the CPU is holding your machine back why not just have two of them?

The logic is simple and obvious, the implementation is anything but. Memory limitations based on our operating systems, hard drive capacity limitations based on the the difficulty increasing head sensitivity to a level required to accurately deal with very high areal densities, and of course multiple CPU usage with all the associated difficulties of increased heat, increased power requirements, increased costs, increased die sizes (and thus decreased yields), specialist BIOS support, getting them to talk to each other in a way that's fast enough so as not to wipe out any advantages they have and so the list goes on. The way forward may seem apparent, getting there is a long and tortuous process.

Eventually technology wins through, and today I want to look at a CPU which by its very existence marks a completely new era in personal computing. In life, when you can't get your work done in the time allotted you get an assistant in, and AMDs new Athlon X2 follows that premise precisely with what is essentially two CPUs in a single package each handling a share of the processing burden.

As you've probably guessed by now, things aren't quite as simple and clear-cut as I've made out. There needs to be support for multiple CPUs at the operating system level, an area where Linux has traditionally had a distinct advantage over Windows.

You applications also need to support for "multithreading", the term used to mean the division of workload between several discrete "logical" processors. Without this, one processors works up a sweat while the other one sits watching it.

There's some speculation currently that the new XBox 360, along with its triple, dual-core processors will mean a plethora of games on the market all written from the ground up with full support for multithreading, though how easy it will be to port these across and make them work as expected on a single dual-core PC remains to be seen. In theory, being a PowerPC processor should mean XBox 360 games make it first to, and run better on the Mac, but history has shown that using the same processor in a platform that isn't supported natively isn't a guarantee of fast gaming performance. Having said that, the fact that early XBox 360 demos were being run on a pair of G5's makes the Mac's gaming future look a little brighter at least, and will hopefully got at least some way to making multithreaded gaming the norm rather than the exception.

Anyway, back to the plot, and the subject of today's review which is an AMD Athlon 64 X2 4800+. Taking its part in a lineup of four new dual-core processors, the 4800+ takes top honours like this:

The prices certainly look scary, but compare them to the cost of splashing out on two processors of the same frequency, which is essentially what you're buying, and they start to look a lot more reasonable.

You'll notice that although there are four speed ratings, there are in fact only two frequencies available, the slower rated of which comes with 512K of cache per core while the faster rated of the two comes with 1MB of cache per core.