AMD Athlon XP

Athlon: The Next Generation

Today marks the launch of AMD's latest desktop processor, the Athlon XP. Also known as Palomino in some quarters, technology-wise Athlon XP isn't the jump from the original Athlon that the Pentium 4 was from Pentium III, but it still beats off its main competitor. Athlon XP is likely to appeal to the average consumer for several reasons. For starters it's much faster than its rivals, beating every other desktop processor on the market hands down - the 1.53GHz part performs well in excess of Intel's 2GHz Pentium 4. Moreover, you don't have to break the bank to get hold of one. If you own a KT133A motherboard or any of the present DDR motherboards on the market, you can expect a relatively painless upgrade to Athlon XP. Some boards will require a BIOS update, but many recent boards recognize the chip without any messing around. And the processor itself is barely half the cost of a Pentium 4. For AMD though, the battle is not yet won. It has beaten Intel in the laboratory, as we will soon discover, but standing in the way of success is a very tricky marketing dilemma. How do you explain that your processor operates at a lower speed, retails for a fraction of the price of its main competitor, and yet outperforms it? Joe Gamer isn't going to swallow that. AMD's answer is PR ratings. These have had a lot of negative press lately, but they are the logical answer to the riddle.

When is PR not PR?

Processor performance is gleaned from the amount of work done per clock cycle, multiplied by the total number of cycles per second. The key to the Athlon XP's success is that it gets an awful lot more work done per clock than the original Athlon, which in turn does a darn sight more than the Pentium 4. PR ratings are there to advise the consumer how much more work the processor does compared to the original Athlon. A 1.53GHz chip for example is being called an Athlon XP 1800+, because AMD feel its performance is equivalent to an Athlon running at 1800MHz, if such a thing existed. The PR ratings you will notice have dropped MHz and GHz tags altogether. This is because AMD believes the average consumer finds these confusing. Athlon XP is being introduced at PR ratings of 1500+ (1.33GHz), 1600+ (1.4GHz), 1700+ (1.47GHz) and 1800+ (1.53GHz). The other question of marketing was how to sell the Athlon XP as a 'new' processor. It uses the same basic technology, it looks the same, it even costs virtually the same. What makes it worth owning? To this end AMD have quantified all of XP's improvements into one inexplicably clichéd marketing device: AMD Athlon XP with Quantispeed Technology. What is Quantispeed technology? The ability to execute nine things at once as opposed to Intel's six, using new super scalar microarchitecture; a super scalar fully pipelined floating point unit; and the ability to get data in faster using Translation Lookaside Buffers and hardware data pre-fetch. In English? More bang per buck. And Athlon XP also introduces 3Dnow! Professional, 52 new instructions that help to keep things faster than a Pentium 4, with full SSE compatibility.

Under the bonnet

That about wraps up the marketing side of things. When we first heard about Athlon XP though, the questions we wanted to answer were to do with cooling, power consumption and performance. In recent times, AMD has made some very hot processors. Puns aside, Athlon has been known to fry before the anxious owner knows anything about it. Snag your fan's power cable between chip and heatsink (something everyone's done now and again) and the chances are that your new chip will give up the ghost in very short order. A leading hardware journalist even fried a few Athlons in front of the camera to show just how dangerous they can be. The good news is, AMD have faced this problem head on and come out smiling. This also leads us on to the other point; power consumption is some 20% lower than for the original Athlon, which means that the chips don't get quite as hot. In actual fact, we found that in the day to day running of our test machines, the Athlon XP was actually cooler than a Pentium 4. This means less vigorous active cooling is required (say goodbye to that 7000RPM fan), and aside from that the chips also now know to react to rapid temperature changes by slowing themselves down to a crawl or switching off completely instead of simply carrying on until they melt. By taking advantage of the new thermal diode, which will appear on forthcoming XP-compatible motherboards, consumers can be assured that if the worst should happen and that heatsink clip flies off, their processor will compensate.

Speed freaks

Ultimately though, the important question for consumers is whether Athlon XP is a belter or not. Whether it can kick sand in the eyes of Pentium 4 and spit on its predecessors. Whether it lives up to those PR ratings. Well, we feel that it does. As you can see from our dramatic benchmark results, Athlon XP outperforms its rivals by a big margin. We used SiSoftware's Sandra 2001 benchmark suite to test the performance of the CPU and memory subsystems, and we also used tests like 3DMark 2001 and the ailing Quake 3 to measure gaming performance, along with newer games such as Return to Castle Wolfenstein, which push your computer harder. We used a GeForce 3 Titanium 500 in all our gaming tests to ensure there were no bottlenecks in the graphics system. Apart from that, we tried encoding an MPEG4 movie, and finally we had a bash at overclocking the processor. Enjoy the graphs. Overclocking isn't especially dangerous these days. If a chip doesn't want to run at a particular speed it won't, and perhaps you will have to reset your BIOS options. Otherwise, it's analogous to running - you can often run a lot faster than you generally do, but the harder you push yourself the more likely you are to have trouble sustaining it. That said, you don't often have to pencil links to run, but you do with the new Athlon XP. Our chip, an XP1800+, running at 1.53GHz by default, was able to achieve an extra 100MHz or so, but we made no real effort to sustain anything higher than that. It's safe to say that there is some headroom.

Conclusion

Is the Athlon XP the sort of processor one should be looking out for this Christmas? The benchmarks really speak for themselves. If you are in the market for a new processor, wait a month or so and buy yourself one of these. The chances are it works on your old kit too. A festive upgrade doesn't have to mean the entire computer, and based on our experience with it, the Athlon XP is a darn sight better than the alternative.

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Benchmarks