AMD Athlon X2 review

The Athlon brand is getting decidedly long in the tooth, but the current crop of dual-core, 64-bit, 65nm processors is anything but behind the times.

Yet, the Athlon’s history is clearly visible in the current line-up. Most lower and mid-range parts are based on the G1 and G2 Brisbane revisions of the chip, with a thermal design power of 65W. But a few parts haven’t been updated. If you see an Athlon 64 X2 3800+ or 4600+ at retail, be warned: these models still use the older 90nm core. Some variants of these old models also have a larger L2 cache – 1MB as opposed to the current standard of 512KB – but overall performance is no better than a modern Athlon. We’ve excluded these outdated parts from our tests.

The most powerful Athlons use an older stepping, too. The 5600+, 6000+ and 6400+ are based on the 90nm F3 Windsor core, with a comparatively high TDP of 89-125W. For now, though, these are AMD’s most powerful offerings, with the top-end parts beating even the Phenoms in our benchmarks, and we don’t see them going anywhere soon, so they’re still well worth a look.

The situation is further complicated by a newer range of Athlons. AMD has recently dumped the 64 designation (since all Athlons are now 64-bit) and moved away from the old numbering scheme. Its new system, though, is no less arbitrary: the three latest models to be released are named the BE-2300, BE-2350 and BE-2400. They’re direct equivalents of the Athlon 64 X2 3600+, 4000+ and 4400+ respectively, but they have a low TDP of just 45W, as opposed to the 65W of the older parts. In use, we’ve found them slightly slower than their full-power counterparts, despite being based on the same Brisbane core, and for now they’re also more expensive. At present, therefore, they’re only a smart choice if saving 20W is a big deal to you.

Finally, you’ll notice a processor with the strange model number 4850e. This is the very newest Athlon, and its specifications indicate that it’s really the next chip up from the BE series of processors. It looks like AMD is already backing away from its new naming system, perhaps because the lower numbers implied that its new processors were less powerful. As we go to press, pricing is yet to be determined, but unless it’s unexpectedly low the same caveats apply as with the BE series.

Taken as a whole, the Athlon range is appealing. The chips sell for very reasonable prices, incorporate modern technologies including virtualisation and data execution protection and, with the possible exception of the very cheapest models, they deliver ample power for everyday use. The real bargain this month is the 4800+, which drove our system to an overall benchmark score of 0.99 for just £42.

As always with CPUs, bang per buck drops off as you move up the range – you’ll pay more than double for a 6400+, which is only around 50% faster. But even the high-end parts stack up well against competing offerings from Intel: the nearest equivalent from Intel’s range is the Core 2 Duo E6750, which achieved a slightly lower benchmark score (1.36 against 1.39) and costs £8 more.

The Athlon also holds up well against Intel’s cheaper processors – as the graph on p88 shows, for every Pentium Dual-Core there’s a comparable Athlon. And although at the low end the Celeron Dual-Core is cheaper by a whisker than its Athlon counterpart, when it comes to more substantial computing the AMD chip is better value than any of the Core 2 Duo E4000 range.

If the Athlon has a weakness, it’s a lack of really high-end parts. AMD’s top score of 1.39 is nothing to be ashamed of, but this month we’ve seen better scores from a host of Intel processors, many of them using less than half the Athlon’s TDP. Of course, these processors cost more than the Athlon – in some cases a lot more. But if you’re looking for a new processor for intensive use – gaming, video processing and the like – an Athlon isn’t the obvious choice.