The Pentium 4 has come a long way since its introduction in the Fall of 2000. It went from being a laughable performer, to a CPU embraced by the community. Today Intel is extending the Pentium 4 family with the third major revision of the chip – codenamed Prescott.

Back when Prescott was nothing more than a curious block on Intel’s roadmap, we assumed that history would repeat itself: Intel would move to a smaller, 90nm process, double the cache and increase clock speeds. Intel has always historically behaved this way, they did so with the Pentium III and its iterations, and they did so with the first revisions of the Pentium 4. What we got with Prescott was much more than we bargained for.

Intel did move to a 90nm process, but at the same time didn’t produce a vastly cooler chip. Intel did double the cache, but also increased access latencies – a side effect we did not have with Northwood. Intel also moved to Prescott in order to increase clock speeds, however none of those speeds are available at launch (we’re still no faster than Northwood at 3.2GHz) and Intel did so at the expense of lengthening the pipeline; the Prescott’s basic Integer pipeline is now 31 stages long, up from the already lengthy 20 stages of Northwood. With Prescott, many more changes were made under the hood, including new instructions, some technology borrowed from the Pentium M and a number of algorithmic changes that affect how the CPU works internally.

If you thought that Prescott was just going to be smaller, faster, better – well, you were wrong. But at the same time, if you view it as longer, slower, worse – you’re not exactly on target either. Intel has deposited a nice mixed bag of technology on our doorsteps today, and it’s going to take a lot to figure out which side is up.

Let’s get to it.

Pipelining: 101
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  • terrywongintra - Monday, February 02, 2004 - link

    anybody benchmark prescott over northwood in entry-server environment? i'm installing 3 servers later by using intel 875p (s875wp1-e) entry server board n p4 2.8, need to decide prescott or northwood to use. Reply
  • sipc660 - Monday, February 02, 2004 - link

    i don't understand why some people are bashing such a good inovation that was long overdue from intel.

    a pc that doubles as a heater and at only 100-200W power consumption.

    Let me remind you that a conventional fan heater eats up a kilowatt/hour of power.

    Think positive

    * space reduction
    * enormous power savings (pc + fan heater)
    * extremly sophisticated looking fan haeter
    * extremly safe casing. reduces burn injuries
    to pets and children.
    * finely tunable temperature settings (only need
    to overclock by small increments)
    * coupled with an lcd it features the best
    looking temperature adjustment one has ever
    witnessed on a heater
    * child proof as it features thermal shutdown
    * anyone having a laugh thus far
    * will soon feature on american idol
    the worst singers will receive one p4 E based
    unit each. That should make people
    think twice about auditioning thus making
    sure only true talent shows up.
    * gives dell new marketing potential and a crack
    at a long desired consumer heating electronic
    * amd is nowhere near this advancement in thermal
    thechnology leaving intel way ahead


    hope you enjoyed some of my thoughts

    Other than that good article and some good comments.

    on another note i don't understand why people run and fill intels pockets so intel can hide their engineering mistakes with unseen propaganda, while there is an obvious choice.

    choice is Advanced Micro Devices all until intel gets their act together.

    go amd...
    Reply
  • Stlr22 - Monday, February 02, 2004 - link

    INTC - "Intel roadmap says Prescott will hit 4.2 GHz by Q1 '05. My guess is that it is already running at 4 GHz but just needs to be fine tuned to reduce the heat."


    Maybe they are trying to keep it under the 200watt mark? ;-)
    Reply
  • INTC - Monday, February 02, 2004 - link

    I think CRAMITPAL must have sat on a hot Prescott and got it stuck where the sun doesn't shine - that would explain all of the yelling and screaming and friggin this and friggin that going on. "Approved mobo, approved PC case cooling system, approved heatsink & fan - and you better not use Artic Silver or else it will void your warranty..." gee - didn't we just hear that when Athlon XPs came out? It brings to mind when TechTV put their dual Athlon MP rig together and it started smoking and catching on fire when they fired it up the first time on live television during their show.

    Intel roadmap says Prescott will hit 4.2 GHz by Q1 '05. My guess is that it is already running at 4 GHz but just needs to be fine tuned to reduce the heat. I bet the experts (or self proclaimed experts such as CRAM) were betting that Northwood could not hit 3 GHz and look where it is at today. Video card GPUs today are hitting 70 degrees C plus at full load but they do fine with cooling in the same PC cases.
    Reply
  • CRAMITPAL - Monday, February 02, 2004 - link

    Dealing with the FLAME THROWER's heat issues is only one aspect of Prescott's problems. The chip is a DOG and it requires an "approved Mobo" and an "approved PC case cooling system", a premo PSU cause the friggin thing draws 100+ Watts and this crap all costs money you don't need to spend on an A64 system that is faster, runs cooler, and does both 32/64 bit processing faster. How difficult is THIS to comprehend???

    Ain't no way Intel is gonna be able to Spin this one despite the obvious "press material" they supplied to all the reviewers to PIMP that Prescott was designed to reach 5 Gigs. Pigs will fly lightyears before Prescott runs at 5 Gigs.

    Time to GET REAL folks. Prescott sucks and every hardware review site politely stated so in "political speak".
    Reply
  • Stlr22 - Monday, February 02, 2004 - link

    ((((((((((((CRAMITPAL)))))))))))))))




    It's ok man. It's ok. Everything will be alright.


    ;-)
    Reply
  • scosta - Monday, February 02, 2004 - link

    #38 - About your "Did anyone catch the error in Pipelining: 101?".

    There is no error. The time it takes to travel the pipelane is just a kind of process delay. What matters is the rate at witch finished/processed results come out of the pipeline. In the case of the 0.5ns/10 stage pipelane you will get one finished result every 0.5ns, twice as many as in the case of the 1ns/5 stage pipeline.

    If the pipelines were building motorcycles, you woud get, respectively, 1 and 2 motorcycles every ns. And that is the point.
    Reply
  • LordSnailz - Monday, February 02, 2004 - link

    I'm sure the prescotts will get hotter as the speed increases but you can't forget there are companies out there that specializes in this area. There are 3 companies that I know of that are doing research on ways to reduce the heat, for instance, they're planning on placing a piece of silicon with etch lines on top of the CPU and run some type of coolant through it. Much like the radiator concept.

    My point is, Intel doesn't have to worry about the heat too much since there are companies out there fighting that battle. Intel will just concentrate on achieving those higher speeds and the temp control solution will come.
    Reply
  • scosta - Monday, February 02, 2004 - link

    You can find thermal power information in the also excelent "Aces Hardware" Prescot review here:
    [L=myurl]http://www.aceshardware.com/read.jsp?id=60000317[/l]

    In resume, we have the following Typical Thermal Power :
    P4 3.2 GHz (Northwood) - 82W
    P4E 3.2 GHz (Prescot) - 103W

    Note that, at the same clock speed and with the same or lesser performance, the Prescot dissipates 25% more power than Northwood. This means that with a similar cooling system, the Prescot has to run substancially hoter.

    As AcesHardware says,
    [Q]After running a 3DSMax rendering and restarting the PC, the BIOS reported that the 3.2 GHz Northwood was at about 45-47°C, while Prescott was flirting with 64-66°C. Mind you, this is measured on a motherboard completely exposed to the cool air (18°C) of our lab.[/Q]

    So, what will the ~5GHx Prescot dissipate? 200W ?
    Will we all be forced to run PCs with bulky, expensive, etc, criogenic cooling systems?. I for one wont. This power consumption escalation has to stop. Intel and AMD have to improve the performace of their CPUs by improving the CPU archytecture and manufacturing processes, not by trowing more and more electrical power at the problem.

    And those are my 2 cents.
    Reply
  • CRAMITPAL - Monday, February 02, 2004 - link

    Prescott will never go above 3.8 Gig. even with the 3rd revision of the 90 nano process. Tejas will make it to just over 4.0 Gig. with a little luck but it won't be anything to write home about either based on current knowledge.

    Intel has fallen and can't get it up!
    Reply

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