With Intel unwilling to commit solely to Direct Rambus DRAM for its new chip, support for DDR SDRAM may be necessary if the P4 is to compete on a par with Advanced Micro Devices Inc.'s Athlon processors -- which are already pledged to DDR through their core-logic interface.

According to analysts, including Bert McComas of InQuest Research Inc. in Gilbert, Ariz., Intel's decision to tie its next-generation Pentium to PC133 memory will compromise performance relative to the Athlon, and almost requires that Intel move to adopt a DDR interface as well.

As AMD's DDR-equipped Athlon nears its launch this fall, Intel is edging closer to Taiwan's third-party chip set makers in an effort to secure a DDR chip set supply line to support the P4, according to sources. Intel itself is contractually barred from developing its own core-logic chip sets to interface to DDR until 2003, according to terms of its licensing contract with Direct RDRAM designer, Rambus Inc. in Mountain View, Calif. (see July 18 story).

Though some observers believe Rambus can ill-afford to severe ties with its chief supporter, others note that competitive pressure within Intel's chip set and microprocessor divisions is building to such a level that a break with Rambus may be on the horizon. Benchmark test data posted recently to Intel's Web site revealed its 815e/PC133 chip set outperforms the 820/Direct Rambus duo, which could hardly be seen as encouraging by its partner.

Despite Intel's announcement on Tuesday, it is still unclear what version of the Pentium 4 will use PC133: the high-end version designed for servers, a mainstream desktop-PC follow-on expected next year, or both. Sources said the P4 is being developed with a 133-MHz front-side bus -- as well as previously announced 100-MHz FSB -- enabling Intel to ensure a clock match to either PC133 or PC266 DDR.

In the meantime, Santa Clara-based Intel needs a mainstream desktop processor with up to 1.4-MHz speed to compete against AMD's Athlon, which will be at this speed later this year. As previously reported, Intel has pumped new life into its venerable Pentium III core, looking to unveil a new 0.13-micron shrink version as quickly as possible to fill the void until its mainstream P4 comes out next year.