Intel to Dump Pentium 4 in Favor of Pentium M

Opinion writes "According to The Register, Intel is to dump its Pentium 4 plans in favour of the new Pentium M architecture. The scrapped Tejas and Jayhawk processors represented Intel's next-gen 90nm P4 CPUs, due to arrive in 2005."

Comments

Power consumption is important

[cpghost]

The more laptops out there, the more important are power saving CPUs. Pentium-M's are a good step in the right direction after the P4 90nm debacle.

Even in the server market, cutting on power consumption is getting more and more important. If you have a park of 1000+ machines in a data center, power consumption matters.

Re:Power consumption is important

[getch();]

The issue of power consumption is rapidly becoming much more significant than even the parent poster realizes.

The general dynamic power (operating power) equation for CMOS circuits has switching frequency as a squared term. Voltage and junction capacitance (think die size here) are also present, but are not squared.

If Intel were to take the P-IV architecture as far as it had planned, an extra few bucks for electricity would be the least of its worries. Without some unforseen advancement, power per unit area would become a (relatively) intractable problem. Even though voltage and die size would probably decrease, the increase in frequency coupled with the reduced area would likely provide a serious problem for cooling. I've read papers that have estimated that air cooling won't be able to dissipate much more heat than it's already required to. Taken far enough, the head produced could just vaporize the silicon (obviously that's not occurring in the near future).

In short: good move, Intel.

Re:Religious Nomenclature?

[kmcmartin]

iirc, the Pentium M was designed at Intel's Israeli division, so this makes some sense compared to the old Washington/Oregon naming scheme.

Return of the son of the revenge of the P6

[zsazsa]

Wow. This is amazing. The P6 (PPro, PII, PIII) architecture is coming back to the desktop. This does make pretty good sense. The P6 has high IPC, and by applying some Pentium 4 tricks (Quad-pumped FSB, longer pipeline), this can make for a killer CPU. For more information, check out this Ars Technica Article on the Pentium-M's P6 heritage. The chip doesn't even lie about it - its CPUID reports a P6 family CPU.

Re:Lemme guess...

[mcbridematt]

Current breed of Pentium M's are pin-for-pin compatible with Socket 478 Pentium 4's, but appear to use a different type of GTL+ signalling. I guess that Intel will release a Pentium M version for LGA 778 (the new socket).

Finally, Intel realises that some long pipeline design with zero decent hardware rotation (up to Prescott), requiring huge cache and big clockspeed isn't that good.

Re:Intel is so far behind anyway

[LocoBurger]

The Pentium M is based on the same P6 core as the Pentium Pro through the Pentium III.

The really interesting part about this story is that Intel is going from their seventh generation architecture (Pentium 4) back to their sixth generation architecture (Pentium Pro/II/III/M).

We all knew this Pentium 4 thing would go nowhere.. :) except for the millions and millions of dollars it got Intel. Now they're trying to gracefully back out. It seems like a sound technical decision. I say good for them.

Re:braniac vs. speed demon

[bhtooefr]

About 5GHz is the upper limit for processors running on EXPERIMENTAL technology available currently. The Pentium-M performs as well as the P4, but at MUCH lower clock speeds, which also means lower heat.

The long pipelines allow higher clock speeds (shorter paths for current to flow down) at the expense of Instructions Per Clock (for a very rough estimate of the efficiency of a CPU, multiply clock speed * IPC).

Re:hrm

[Cyno01]

Not smaller fans, slower fans. A smaller fan runnign the same RPM as a large fan will move less aire with the same amount of noise, a large fan can move the same amount of air at much smaller RPMs than the small fan, and in doing so generate less noise. My case has 1 120mm fan and 1 92mm fan, it probably pushes the same amount of air as my friends setup which has 4 80mm case fans, but with substantially less noise.