Pentium 4 ships amid doubts over Rambus

Intel has started shipping its Pentium 4 microprocessor amid signs that its commitment to Rambus memory technology is weakening.

Pentium 4, which is released today at clock speeds of 1.4Ghz and 1.5Ghz, will ship with 128Mb of Rambus Dynamic Access Memory (RDRam), which Intel said will give it high-bandwidth performance that other memory technologies are not able to approach.

Intel has confirmed it is looking to use memory technologies other than Rambus, which it had planned to use exclusively with its forthcoming semiconductor technology, with future versions of its Pentium 4 microprocessor.

John Woodget, Intel's director in Northern Europe, said Pentium 4 represents a performance milestone for the chip maker because it brings together a different micro architecture, an additional instruction set (SSE-2) and a redesigned 400Mhz system bus. Together they give "headroom" on system performance, with up to 3.2Gb of data per second, he added.

The NetBurst micro-architecture includes Hyper Pipelined technology, which is twice the length of the micro-architecture in the Pentium III - significantly increasing processor performance and frequency stability.

Never before has Intel included three design changes in the release of a processor, said Woodget, who added that Intel expects sales of Pentium 4 to rival that of Pentium III by 2002.

Turning to future development, Woodget said Intel is also considering using Double Data Rate (DDR) memory technology. This would involve designing a separate chipset to the Intel 850 chipset.

"The RDRam memory interface is high-performance, high-end technology but for users who are prepared to compromise, and as we ramp production up we'll look at DDR - even though you won't get the bandwidth with that technology," said Woodget.

The remarks follow comments by analyst Gartner earlier this month that Rambus will be dead in six to eight months because it has failed to move out of the high-end workstation market.

Persistent reports of problems with the manufacture of Rambus, its speeds and high cost, have resulted in a split in the market, with many memory manufacturers backing both Rambus and DDR memory technology. DDR improves PC performance substantially and does not cost much more to produce than the older SDRam (Synchronous Dynamic Random Access Memory) technology.

The issue is important because it affects system pricing, with Pentium 4 systems expected to ship at between $1600 and $2600.

Woodget added that Intel expects systems to be popular with gamers, who will appreciate the greatly improved graphics and streaming content capabilities, as well as knowledge workers, such as City traders, for business visualisation.

However, Jonathan Eales, workstation programme marketing manager at Compaq, said finance houses are traditionally conservative, and he expects more demand from CAD users, when its production expands around the turn of the year.