Mainboards Blamed for Intel’s New Quad-Core Microprocessors' Delay.

[SRTDodge05]

The delay of Intel Corp.’s new breed of microprocessors manufactured using 45nm process technology was not caused by an error in chips, but was necessary to ensure compatibility of new central processing units (CPUs) with already available mainboards.

As reported, Intel decided to postpone the commercial launch of its microprocessors made using 45nm process technology recently due to issues with processor system bus (PSB). According to a news-report from PC Watch web-site, the issues with quad-core code-named Yorkfield processors occur on affordable mainboards that utilize 4-layer print-circuit boards (PCBs) and do not affect expensive platforms that are based on 6-layer PCBs. As a consequence, the world’s largest producer of x86 processors decided to create a new version of its chips to retain compatibility with mainstream motherboards.
Nowadays the majority of Intel’s quad-core microprocessors for desktops – which consist of two dual-core dice on a single piece of substrate – utilize 1066MHz processor system bus and only two Intel Core 2 Extreme processors QX6850 and QX9650 use 1333MHz PSB. Since Intel’s “extreme” chips that retail for over $1000 a unit are installed into expensive mainboards, no problems occur. In fact, Intel Xeon processors, some of which feature 1600MHz PSB, also do not have any troubles with such high speed. But apparently current design of Intel Core 2 Quad microprocessors with 1333MHz bus made using 45nm technology results in excessive “PSB noise”, which prevents normal operation.

X-bit labs - Mainboards Blamed for Intel’s New Quad-Core Microprocessors' Delay.

[ctal]

As a long-time electrical engineer in digital circuit design, this strikes me as a very plausible explanation, one which is more likely to be true than most of the rumors and speculation which have been circulating on the net about this issue.
-- Al

[bajo]

I can wait a loooong time this time, hope they make a killer line ...again