If you read our article relating to the wonderful ability of certain AMD XP1700 CPUs, ones with a JIUHB nomenclature, you'll know that in certain circumstances the CPUs' speed ratings don't count for very much. AMD has now put most of its performance desktop eggs into the Barton basket. The Barton core, characterised by an extra 256kb of L2 cache, a minimum 166FSB running speed and precious little else, is AMD's answer to Intel's latest line of Hyper-Threading P4s. AMD, whether rightly or wrongly, decided to jack up the Barton's XP rating another notch, simply to reflect its increased performance over a regular Thoroughbred-based XP. What all that meant was even seasoned, informed users had to consult a handbook or website to determine the CPUs' actual running speeds. Confusing, eh ?.
At the time of writing this article, four Barton-based processors were available from AMD, all in quantity. The little table below should highlight the attributes of each.
|AMD Name||Clock speed||Front-Side Bus||Multiplier|
|XP3200+||2.2GHz||200 (400MHz DDR)||11x|
|XP3000+||2.17GHz||166 (333MHz DDR)||13x|
|XP2800+||2.083GHz||166 (333MHz DDR)||12.5|
|XP2500+||1.83GHz||166 (333MHz DDR)||11x|
Intel and many others would argue that a processor that was 117MHz faster than one lower in the range, albeit with a faster FSB (XP3200+ vs. XP2800+), shouldn't attract such a comparatively high performance rating. We'll let AMD answer that one.
The most interesting CPU out of the Barton range, we feel, is the XP2500+. By dent of its lower speed rating, it also causes considerably less damage to your wallet. Tentative pricing puts it at around the £70 mark. Compare that with £330+ for the range-topping XP3200+.
One may say, quite rightly, that its lower speed deserves such a low price. But let's not forget that is a bona fide Barton CPU, and it carries all the benefits of the higher priced versions (XP3200's 200FSB excluded).
What if its rating belies its potential ?. What if the core was of the same quality found on the more expensive models ?. What if it could manage to attain and beat any standard Barton's speed with a little bit of overclocking ?. Those what ifs, if substantiated, would make this £70 CPU a bargain of immense proportions. One would suspect that AMD would not be generous enough to place high quality XP3200-capable cores on a 'cheap' Barton, but matching yields and demand is an extremely difficult task. We'll now take a look at a 'special' Barton XP2500+, and we'll see if it has the potential of being a real star.