Rivals Advanced Micro Devices Inc. and Intel Corp. are upping the ante with faster processor frontside-bus (FSB) speeds to boost desktop PC performance.
AMD last week unveiled its Athlon XP 3200+ processor with a 400MHz FSB. And this week, Intel is expected to debut its 865 Springdale chipset supporting a quad-pumped 800MHz FSB for mainstream desktops.
The FSB speed hikes are the latest in a series of increases over the past several years, all aimed at easing the memory bottleneck and taking advantage of ever greater processor performance.
AMD moved up from its mainstay 333MHz FSB and Intel will jump from a 533MHz FSB used in most of its mainstream Pentium 4 processors.
In addition, Intel will extend its HyperThreading technology to a wide range of desktop Pentium 4 processors starting at 2.4GHz clock speed.
Up to now, only desktop HyperThreading capability has been offered with the high-end 3- and 3.06GHz Pentium 4s.
The difference in FSB speeds sparks another marketing battle between the MPU combatants, with AMD claiming the performance of its processors more than makes up for having half the FSB speed of Intel's. Just as AMD countered higher Intel processor clock frequencies with its processor performance ratings, the company maintains that FSB speed is only one factor in ranking MPUs.
Christopher Doran, Athlon brand manager at AMD, said the Athlon bests the Pentium 4 with larger 128Kbyte on-die L1 cache, more instructions per clock cycle, and fewer pipeline stages.
"Bigger processor clock frequency and FSB speed numbers alone don't mean better performance. We focus on the end result of overall processor performance,"Doran said.
Intel shied away from talking about an official launch date for Springdale and the 800MHz FSB, but analysts have openly said the introduction is this week. Intel hasn't been reluctant to talk about the 800MHz FSB's features, which a spokeswoman said "will allow memory to take advantage of the greater performance available in the processor."
Intel last April unveiled its first 800MHz FSB in its 875 Canterwood chipset, but only for support of the newest high-end 3GHz Pentium 4. This week's Springdale chipset introduction will extend the 800MHz FSB and dual-channel DDR400 memory to mainstream Pentium 4 desktop processors, according to sources.
Intel is also expected to unveil Pentium 4 processors at several speed grades--2.4, 2.6, and 2.8GHz--to work with the new 800MHz FSB and Springdale chipset.
"Intel is bringing the high-performance 800MHz FSB into the more affordable price points of the mainstream PC market," said Nathan Brookwood, an analyst at InSight 64, Saratoga, Calif.
In contrast, AMD said its 400MHz FSB initially will support only its highest-performance Athlon XP 3200+ processor. The company said it would add the 400MHz FSB to processors operating at lower speed grades, but only if there is strong customer demand.
FSB technology will not be available in AMD's next-generation 32/64-bit Athlon 64 processors, which it plans to roll out in October. Doran said the processors will embed the memory controller on the processor die, eliminating the need for an FSB.
Some analysts surmised that AMD's projected Athlon 64 spurred Intel to accelerate its 800MHz FSB for mainstream desktop processors.
Intel, they said, was planning to introduce its 800MHz FSB to counter AMD's Athlon 64 launch this spring. Even though AMD has pushed back the introduction to October, Intel isn't going to wait, said Kevin Krewell, an analyst at In-Stat/MDR, San Jose.
"Intel had the 800MHz FSB ready to go and decided to go ahead with the planned launch now anyway," he said.
An Intel spokesman responded, "We drive technology forward to meet customer requirements, regardless of what competitors do."
The latest FSB speeds from both AMD and Intel support DDR400 memory now preparing to go to market.
Third-party manufacturers are also rushing out new chipsets. Intel has given licenses to Silicon Integrated Systems (SiS) Corp., Via Technologies Inc., Acer Inc., and ATI Technologies Inc., all of which have announced chipsets to support the new Intel processors. And SiS, Via, and Nvidia Corp. said they will have chipsets supporting the new AMD AthlonXP 3200+.