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Intel to Dump Pentium 4 in Favor of Pentium M

Posted by ryuzaki0 on from the now-30%-lower-electricity-bills dept.

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."

14 of 413 comments (clear)

  1. Power consumption is important by cpghost · · Score: 5, Informative

    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.

    --
    cpghost at Cordula's Web.
    1. Re:Power consumption is important by getch(); · · Score: 5, Informative
      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.

  2. Re:Religious Nomenclature? by kmcmartin · · Score: 5, Informative

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

  3. More info by Groo+Wanderer · · Score: 3, Informative

    There is more on The Inq here:
    http://www.theinquirer.net/?article=15749
    http://www.theinquirer.net/?article=15760
    http:// www.theinquirer.net/?article=15768

    And more coming soon, this story is far from over.

    -Charlie

    Disclaimer: I write for The Inq, but I did not do these stories.

  4. Return of the son of the revenge of the P6 by zsazsa · · Score: 4, Informative

    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.

    1. Re:Return of the son of the revenge of the P6 by barawn · · Score: 3, Informative

      Quad-pumped FSB, longer pipeline

      A quad-pumped FSB might make sense, although I doubt that the PM is actually all that memory-hungry, as the old P6s weren't, and neither were the Athlons.

      A longer pipeline is virtually the definition of the P4 - it has one of the (if not the) longest pipelines in desktop processors anywhere. A long pipeline is what causes low IPC.

      I really doubt that they'll lengthen the PM's pipeline much. Look at the Athlon XP -> Athlon 64 evolution - the pipeline was only stretched by a couple of clock cycles.

      This is a curious point for Intel, as processors can't continue to get faster in a simple way - the heat issues are just too large right now. The PM will probably start getting the standard tricks that others are playing - hyperthreading, like the P4s, integrated memory controller, maybe even an L3 cache. But definitely not a long pipeline - that was the P4's mistake.

  5. Re:Lemme guess... by tomstdenis · · Score: 3, Informative

    Socket/Super 7 boards.... I recall having an MI, MII and a K6-2 350 in the same board.

    Of course that would require both Intel and AMD to sit down and design some Socket1000 board or something. But that gets trickier cuz many of the pin [in Socket478 for instance] are grounds and power. IIRC there are 166 pins dedicated to power management. So the layout of the actual processor would be dictated somewhat by the location of power.

    But it would be nice to be able to take out an Intel core and slap in an AMD core in the same motherboard...

    Tom

    --
    Someday, I'll have a real sig.
  6. Re:hrm by Shinobi · · Score: 3, Informative

    Smaller fan sounding less than a big fan is all relative. To move the same amount of air in a given time, the small fan needs a far higher rpm, which increases noise.

  7. Re:Lemme guess... by mcbridematt · · Score: 4, Informative

    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.

  8. Re:Intel is so far behind anyway by JDevers · · Score: 3, Informative

    Actually, the Pentium M is NOT a new architecture it is a Pentium III all dressed up for war. More or less it is a P3 with the P4's branch prediction unit, an ever so slightly longer pipeline, and a few other niceties from more modern processor designs.

    See: http://arstechnica.com/cpu/004/pentium-m/pentium-m -1.html for a somewhat technical discussion...

  9. Re:Intel is so far behind anyway by LocoBurger · · Score: 5, Informative

    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.

  10. Re:braniac vs. speed demon by bhtooefr · · Score: 4, Informative

    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).

  11. Re:hrm by Cyno01 · · Score: 4, Informative

    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.

    --
    "Sic Semper Tyrannosaurus Rex."
  12. Re:End of an era? by ball-lightning · · Score: 3, Informative

    IPC = Instructions Per Cycle. Its the amount of work a CPU can do in a clock cycle. (The higher the IPC, the more efficent the processor, which is how AMD's processors can do the same amount of work with a lower clock speed)