Athlon 4 and MP to get XP speed features

The features that collectively make up what AMD calls its Quantispeed technology, launched on Tuesday in the Athlon XP processor, will migrate to the mobile Athlon 4 and to the Athlon MP multiprocessor chips early next year.

Several of the features in Quantispeed, such as the nine-issue fully pipelined susperscalar micro architecture, which lets the chip process nine instructions per clock cycle, are already built into the Palomino core, which the Athlon 4 and Athlon MP use. But these two processor lines will also now get features such as hardware data pre-fetch, which boosts 3D performance.

Speaking in Milan at the launch of the Athlon XP, AMD's group vice president of computational products Dirk Meyer, said he expected the other chips to get the features "by the end of a couple of quarters from now".

The features that make up Quantispeed add about half a million transistors to the 37 million transistors already in the Palomino core. But Quantispeed is also largely a marketing term, a fact which AMD readily admits.

For buyers, the biggest effect is likely to be that AMD's new scheme for indicating processor speeds will also be extended across all Athlon processors. With the introduction of Quantispeed, in the shape of the Athlon XP, AMD is attempting to end the consumer perception that clock frequency is a good indicator of processor performance.

Performance of the Athlon XP range is indicated by the 1500+, 1600+, 1700+ and 1800+ tags that indicate the speed at which a current Athlon, based on the Thunderbird core, would have to run to achieve the same performance. AMD was keen to refute reports the figures indicate the clock frequency, in MHz, that a Pentium 4 would have to run at to achieve the same performance. European director of marketing Robert Steed, said, "If that were the case, then the model numbers [on the Athlon XP] would be much higher."

Launching a broadside against Intel's penchant for clock frequency, Meyer said the days of using this as a reliable indicator of processor performance are gone. "For Intel, the amount of work done per clock cycle increased up to the launch of the Pentium III," he said. "But with the Pentium 4 the picture changed. The Pentium 4 has a lower architectural efficiency for the clock rate [than the Pentium III], so performance can no longer be assessed simply by clock speed. We have reach an inflexion point. Now consumers who have relied for years on clock frequency as an indicator of performance need something else."

The Athlon XP 1500+ actually runs at 1.33GHz, while the 1600+ runs at 1.40GHz, the 1700+ runs at 1.47GHz and the 1800+ runs at 1.53GHz. According to AMD, the current Thunderbird-based Athlon would have to run at 1.5GHz to match an Athlon XP 1500+. Tests by ZDNet appear to bear out AMD's performance claims. Using the processor-intensive SETI (Search for Extra-Terrestrial Intelligence) distributed computing project run by Berkeley, the same test work unit (WU) was processed using a 1.4MHz Thunderbird overclocked to 1,533MHz and an XP 1800+.

Despite running at the same clock speed, the Thunderbird has the advantage because overclocking the frontside bus (FSB) to 146MHz over the standard 133MHz (in order to get the 1533MHz clock speed) also gives a boost to other system components including memory. Despite this, the Thunderbird took 4 hours and 17 minutes to process the unit, while the XP 1800+ took 3 hours 41 minutes.

See Chips Central for the latest headlines on processors and semiconductors.

See the Hardware News Section for full coverage.

Have your say instantly, and see what others have said. Click on the TalkBack button and go to the Chips Central forum

Let the editors know what you think in the Mailroom. And read other letters.