"1.7GHz. It's there. Unless you need it."

Check out this article by Bert McComas.
When you really need processing power, a 1.5 GHz P4 may instantly turn into a 750 MHz processor. That is just so funny.
38 answers Last reply
More about 7ghz there
  1. cool, great link and a recommended read for all...but, for those who are lazy, here is the section of the article that BHC's great post is referring to:

    Pentium 4 Power Management – A Performance Limiter

    Last year, as details of the Pentium 4 were emerging, Intel's elaborate thermal and power regulation requirements for P4 systems raised many eyebrows. Platforms required new power supplies capable of pumping out more current, and enormous copper heat sinks for CPU cooling. Humorous jabs ensued… "Turns your PC into a toaster oven," some said.

    But just prior to the P4 launch, Intel sought to confront the issue by publicizing power specifications for the soon to be released CPU. To many people's amazement, the 1.5GHz Pentium 4 was said to consume only 54.7 Watts - a maximum power dissipation rate well below the fastest Athlon.

    Numerous independent product reviews have quoted this value (and still do) particularly in contrast to AMD's latest 73 Watt, 1.33 GHz Athlon. The only problem is that the quoted Pentium 4 power dissipation figure is wrong - or at least the number is misleading.

    These two specifications are defined under entirely different conditions. AMD reports the true absolute maximum power dissipation rates without constraint. Intel on the other hand, publishes a compromised figure that is open to lots of interpretation. Page 70 of Intel’s P4 datasheet shows the dissimilarity.

    Since most applications are ‘unlikely’ to cause the processor to consume its absolute maximum power, Intel quotes a figure that looks more like a ‘not-to-be-exceeded’ figure. In theory this power level could easily be exceeded under stress tests, benchmarks and particularly challenging application loads. If this were to happen, a thermal diode (required on all P4 platforms) would trigger a power management mechanism that instantly cuts CPU performance, and allows it to cool down.

    The P4 spec reads, “The Thermal Monitor feature … is intended to protect the processor from overheating when running high power code that exceeds the recommendations in this table,” (54.7 Watts for the 1.5GHz model).

    Looking forward, if you buy a 1.7GHz P4, it will run at that speed when it is idle, or under light loads, when CPU utilization is nominal, or in applications that don’t really need a 1.7GHz CPU. But when you drive it to extremes, or wish to extract all available performance from the processor, you may find yourself spontaneously and unavoidably power managed to a lower effective clock speed. Intel’s motto… “1.7GHz. Its there. Unless you need it.”

    Update: Intel’s Thermal Design Guide has revealed that the absolute maximum power dissipation of the 1.5GHz P4 is actually 72.9 watts. This is 33% higher than the published system design specification, and essentially identical to the 1.33 GHz Athlon. In order to prevent the CPU from exceeding 54.7 watt, thermal throttling is used. If performance critical applications drive CPU power above its artificially low 54.7 watt limit, the CPU is halted with a 50% duty cycle (alternating 2 microseconds on; 2 microseconds off) until it cools down. This effectively turns your 1.5GHz processor into a 750MHz processor – just at the moment you demand peak performance. On the other hand, you will probably still be able to check your email at 1.5GHz. This scheme is described on page 23 of Intel’s P4 Thermal Design Guide. Commentary is already floating around the web that perhaps Intel feels guilty about selling 750MHz CPUs in 1.5GHz clothing, and thus has decided to cut the price by 50% as well.
  2. That article is full of misnomers. The Thermal Monitor feature can be used in a number of different ways. Its use is controlled by the motherboard manufacturer and can be added as a BIOS setting.

    For most cases, the thermal control circuit merely provides an added level of safety against unsafe temperature levels. This means it will only activate if the CPU reaches an unsafe temperature, not a certain wattage level. If you provide adequate cooling, you can run at maximum wattage forever at full speed ahead and never trip the protection mechanism. It's based on temperature, not wattage. The writer of that article needs to improve his reading comprehension skills.

    Personally, I think it's a great idea. It's much better than having your CPU fry the way Athlons do. It's better than the best of the old methods, which simply shut down your CPU in event of temperature overload. At least this lets you continue to operate and save your work while informing you of the overheating situation.

    To see the technical details yourself, read here: ftp://download.intel.com/design/Pentium4/guides/24920301.pdf


    -- The center of your digital world --
  3. Raystonn,

    Thanks for the providing more info. I read the section on thermal monitoring. However, I found it is curious that the trip-off temperature is never specified other than it is pre-calibrated in the factory. Since Intel actually specs wattage (e.g. 54.7W for 1.5 GHz P4) but no temperature, could it be that is wattage a P4 would reach the trip-off temperature under normal (Intel's reference) cooling conditions?? If that is the case, this wattage is way below the absolute max power (72.9W for 1.5 GHz), which means under normal cooling, a P4 may not be allowed to take in a full load. In that case, Bert McComas is still correct in his assessment.

    Of course, with "adequate" cooling, one can run at the max wattage at full speed. However, if this "adequate" means "extraordinary", then it is pointless since with "extraordinary" cooling, one can even run 1.3 GHz Athlon at 1.6 GHz.
  4. By the way, I agree that having a safety switch is better than not having one. AMD and others really need to do something in this area. However, a poorly-designed safety switch may drastically reduce the max performance of a CPU can produce, and to think people pay a premium in order to get that performance. That would be very annoying as well.
  5. This is just another reason not to buy a P4. What are they doing about this?

    <font color=red>Computers are useless. They can only give you answers.</font color=red>
    Pablo Picasso
  6. As mentioned in the document to which I previously linked, the point where the thermal control circuit goes active is specified in the processor datasheet. You will find the P4 datasheet here: ftp://download.intel.com/design/Pentium4/datashts/24919802.pdf

    The maximum allowed temperature for a 1.5GHz P4 is 72C. If this temperature is exceeded, the thermal control circuit will become activated to save your CPU from becoming damaged. You will also be notified via ACPI if you are running an operating system which supports this. (Windows does support ACPI.)

    I feel much better about an investment in a P4 knowing I cannot fry it. This will keep countless overclockers from accidentally frying their chips. 72C is extremely hot.


    -- The center of your digital world --
  7. hmmmm, makes me wonder if the ppl who run the benchmarks on the P4 know this and intentionally trick the P4 into throttling down, hmm...just makes me wonder.

    "Amd cpu...Gone in 2 secs flat, it truly is a fast chip!"<P ID="edit"><FONT SIZE=-1><EM>Edited by AmdMeltdown on 04/14/01 04:36 AM.</EM></FONT></P>
  8. Raystonn,

    Thanks again. 72C is indeed high. Now can you clarify what 54.7W (for 1.5 GHz) means? Is it indeed "not-to-exceed" (under normal cooling) or just a marketing lie? Furthermore, if a P4 runs at the absolute max power (72.9W for 1.5 GHz) with normal cooling (Intel's reference heatsink and fan), what will be the temperature? Can you or someone shed some light for us? Thanks.
  9. A quote from Page 28 of Intel's Pentium 4 Thermal Design Guidelines :

    <<A chassis cooling solution designed to the TDP as specified in the Datasheet will adequately cool the processor to a level where activation of the Thermal Monitor feature is very rare or non-existent. Various levels of performance versus cooling capacity are available and must be understood before designing a chassis. Automatic thermal management must be used as part of the total system themal solution.>>

    In other words, this feature will prevent you from frying your CPU when you make a mistake (of installing heatsink, when the fan doesn't work, etc)
  10. This is the wattage that is not exceeded by the CPU during the execution of 99.9% of applications, including intensive benchmarking. A similar number is given by AMD for their CPUs. Neither company's CPU actually has this number as a hard limit on power consumption. Both can go much higher. These occasional higher numbers are called spikes and generally do not contribute greatly to the average wattage used by the CPU.

    It has been shown that you cannot supply adequate cooling for Athlons that run at their maximum power usage. Luckily, this maximum power consumption only lasts a few microseconds during the most intense calculations imaginable. Otherwise there would be many upset Athlon owners with a great deal more keychains.

    Intel CPUs aren't much different in this regard. (You wouldn't expect them to be. They're built using the same materials.) The only difference is that in the off chance it's already very hot and one of these intense spikes from an extremely merciless calculation comes around and actually lasts for a while, you can be guaranteed that your P4 will not be damaged. The same circumstances will damage an Athlon and even a P3.

    This feature in the proper handling of power consumption/heat spikes is actually a great advancement in CPU design. A side affect of mentioning the advancement is actually mentioning the problem that necessitated the fix, about which the general public was completely unaware. This could have the negative PR impact of people relating the power/heat spike issue with Intel rather than properly crediting them with fixing the problem that has plagued all modern processors to date from all companies.


    -- The center of your digital world --
  11. It's possible that Northwood will solve the problem. The 0.13 Micron process should produce much less heat, so this 'ceiling' should be hit less often. Hopefully this is just a temporary feature (like socket 462) that will dissapear or become irrelivant when the 'real' p4 is introduced.

    Why has Intel introduced the p4 at this stage, when it's clearly very immature? I don't know. Maybe they felt that after the 1.13GHz disaster, they needed to keep up with AMD before the Northwood is released (otherwise their reputation could be damaged substantially). If the p4 hadn't been released yet, Intel would be in serious doo-doo, comparing the 1GHz p3 with the 1.33GHz Athlon!

    Did anyone also read the stuff about the poor bus design of the p4 meaning less actual data throughput than the p3?

    ~ I know the human being and fish can coexist peacefully ~
  12. "It's possible that Northwood will solve the problem."

    What problem?

    "Hopefully this is just a temporary feature..."

    Heck no. Hopefully it's a permanent feature. This is not a problem, but a feature. Read into the posts above more carefully.


    -- The center of your digital world --
  13. Raystonn,
    From what you said, it appears the number like 54.7W is the nominal max power (3 sigma??) and there are power excursions will exceed it. Given that the time response of the current comparison circuit should be very fast, I can see if there is a local (on-chip) temperature rise from one of those excursions, the trip-off may be instantly activated, which is not the intended purpose since it really means to be a safety switch. Even if it only happens in very small percentage of cases, it's not good, especially those may be the cases users would want MORE performance, not 50% less. For many years, when we buy a DESKTOP CPU with a certain clock speed, you can be sure the CPU will deliver that speed ALL the time. If a 1.5 GHz P4 does not deliver 100% of the time, what about a (hotter) 1.7 GHz??

    I totally agree having a safety switch is nice, but Intel, AMD and others need to work to reduce the power consumption in addition to the safety switch. I hope once the 0.13 micron technology ramps up, with much smaller die size and lower supply voltage, the power consumption will go way down and make this discussion moot. Of course, power consumption also increases linearly with the clock speed. So, in another year, the problem may show up again.

    That is why I rather see a more efficient CPU architecture than something good for pumping up the clock speed (like P4). If the CPU core is not efficient, you need HIGHER clock speed just to keep up with the competition. But, higher clock speed produces higher power consumption. Eventually, you will have to pay the price. So far, Intel has the advantage of a more advanced IC processing technology, so AMD chips even at lower clock speed do not consume less power. However, AMD is currently into the advancement of SOI (silicon-on-insulator) technology, which greatly reduces the junction capacitance (C) and hence power consumption, and Intel is not. Therefore, Intel may not have the advantage for much longer. Let's wait and see in a couple of years if the P4 design is wise or not.
  14. There will be the occasional moment that this power spec is exceeded, perhaps once in a year. Since the thermal circuit is based on temperature and not wattage, it would have to last for a while and create an exorbitant amount of heat in order for this cirtuit to become active. We're talking 70 degrees Celsius maximum here. That's highly excessive. A spike for a small moment will not cause the CPU to raise in overall temperature to 70C.

    The average user will never, ever, see his CPU temperature reach this level with the standard provided heatsink/fan, even at full throttle running intense benchmarks for a month straight. This thermal technology is meant only as a protection against improperly installed, or broken, heatsinks and fans. Intel took a look at the fry rate of the Athlon and took steps to ensure it would not happen to the P4, ever. This is important from a product quality standpoint.


    -- The center of your digital world --
  15. and AMD took steps to insure that the "fry rate" on their chips go up so that they can sell twice as many in half the time.

    now it's comming all together...hahahahahahahathlon!

    "Amd cpu...Gone in 2 secs flat, it truly is a fast chip!"
  16. Meltdown, you are so irrational. The only way you fry an AMD cpu is if you take it and overclock it by double its manufactured clock speed, install the heat sink wrong, or you don't check and make sure the fan works. I leave the cover off my case all the time so I can see if it works. Oh wow, Intel's CPU's have thermal protection feature on it, who cares! If you overclock and compute responsibly, you won't fry anything.

    Life is hard...Live with it
  17. What is the normal running temp on the P4? I didn't see an answer in this thread. 70C is very high but if the CPU idle's at 55C is 70C very high?
  18. .......... or have the water on your watercooler accidentally shut off. :wink:


    All your RAMBUS are belong t............ ahh screw it
  19. <<< It has been shown that you cannot supply adequate cooling for Athlons that run at their maximum power usage. Luckily, this maximum power consumption only lasts a few microseconds during the most intense calculations imaginable. Otherwise there would be many upset Athlon owners with a great deal more keychains. >>>

    WTF? So those of us that crunch seti fulltime (from pc powerup to shutdown) and crunch DivX etc. at the same time are not running our systems flat out? I can assure you that my system copes with the heat output of my 1.33@1.6Ghz Athlon quite admirably thank you very much.

    -* This Space For Rent *-
    email for application details
  20. My 900@1.13 is nice a frosty with my watercooler when i run seti all day. (has been running about 19 hours straight now i think).


    All your RAMBUS are belong t............ ahh screw it
  21. AmdMeltDown you are missing something here. You can't have it both ways. Either the P4 is throttling down to a dinky 750mhz when you really need the power, or the P4 really puts out 70watts just like the Athlon. If the later is true that means Intel's marketing is just pure bullshit that only narrow-minded people like you would believe. So which one is it?
  22. Raystonn,
    Sorry to be skeptical here. However, I know the heat transfer coefficients within the chip and from the chip to outside are finite. During a power excursion, there could have been a substantial temperature gradient for a short time. Since the thermal monitor circuit is ON CHIP, it will react instantly (well, the speed of electron), but the average temperature of the chip and heatsink etc will hardly change much if the duty cycle of those excursions is quite short as you suggest.

    Let me give you an example. One of the ways to make ultra-shallow transistor junctions for deep submicron transistors is laser anneal. The temperature on silicon surface will reach greater than 1200C, but the laser pulse is short, and total amount of energy is low, the silicon substrate temperature is therefore much, much lower. Because of the finite heat transfer coefficient of silicon, a huge temperature gradient up to 1000C is established to activate impurity dopants and make ultra shallow junctions. The power excursion is not an extremely localized laser pulse. However, the basic idea is the same, and we don't need a 1000C temperature gradient to trip the switch (30C??).

    I don't have any hard evidences to show the throttle down of P4 occurs frequently, but physics is there. All I say is a simple on-chip thermal switch may do more than it is intended. I am open to you to provide some hard evidences to show it is not the case. Thanks.
  23. Good point, being that it is a "thermal diode" one would think that the diode would cut off at a temp, not a wattage. I agree with the errors of the article. In addition it is usually possible to addjust how much and when the cpu is throttled back in BIOS.

    "You're just a heartless computer" <font color=red>"That is correct. What is the problem?" Z.O.E.</font color=red>
  24. "... but the average temperature of the chip and heatsink etc will hardly change much if the duty cycle of those excursions is quite short as you suggest."

    That's the key. The thermal circuit is not triggered until the average temperature on the chip exceeds 70C. These short excursions that do not adversely affect the CPU will not cause the thermal circuit to activate. Only heat that falls just barely short of that required to damage the CPU will activate the thermal circuit. The trigger temperature is set at the maximum safe operating temperature of the CPU, not at soem artifically lowered number..

    You'll never see this triggered unless you have improper cooling such as a broken or inefficient heatsink/fan, a vent is blocked with dust, etc. Would you prefer a fried CPU? You will be notified via ACPI in the event the circuit is triggered, so it's not a silent operation. You will definately know if it's happening. You can then take corrective action for your cooling solution instead of unknowingly shortening your CPUs life.


    -- The center of your digital world --
  25. Raystonn,

    Thanks for your insites.. this is one of the few really informative threads I've read on this forum for quite a while. I have a few questions though:

    Did you do any sort of testing to backup your claims ? I mean, triggering this ACPI event, will it be really 'visible' ? How ? Does any P4 owner here dare try ?
    You claim 'maybe one time a year'. That makes little sense. If you can trigger this thermal circuit once, you can do it all the time by executing the same code. unless you mean to imply a cpu fan fails 'once a year'.. Can you back this up somehow ?

    Secondly.. Im curious to know if a P4 would stand 70°C without locking up.. Most AMD cpu's I've come across wont work above something like 55-60°. They dont fry, they just lock up. Can a P4 still run at 70° ? If not, the protection feature is rather theoretical, since the PC wont be operating anymore.. hence, these cooling instructions wont be executed anymore.

    Lastly :
    <<< It has been shown that you cannot supply adequate cooling for Athlons that run at their maximum power usage. Luckily, this maximum power consumption only lasts a few microseconds during the most intense calculations imaginable >>. Once more, I'd like some more evidence or info. What kind of operations would trigger this maximum power usage ? Ever thought it might be possible to write a piece of code that would constantly execute these operations ? That might result in a CPU busting virus.. no ?
  26. Hate to bring flames to this nice thread but, It seems AMD lemmings are clueless to thermal protection and grasping at anything to put in a bad light. at any cost.

    That article was written by a AMD lemming and you can obviously see what happens when bad information is posted.

    We setup a pair of P4 1.5Ghz running CFD (computational fluid dynamics) for Nasa JPL project for the passed few weeks running 24/7 at full throttle (other than when model/enviroment is changed). These machines have 8 Atlas 10k 4.5ms drives in the same case = alot of heat. The CPU runs at 52C constantly. drops to 48C at idle. but I know it will never see 70C unless HSF fails or all the vents are blocked.

    CFD can be extremely CPU/bandwidth intensive. I use this real life example since its better than guessing like the author of that article is doing.

    WTG on a premo Lemming "jack off all over myself cause im so excited" article. its just another lame attempt from a AMD lemming to spread false information about the P4. If you notice he throws in a few jab. "toaster" quotes 1 benchmark where AMD wins from spec.org along with other AMD angles of Intel bashing.

    get a clue to the use of the P4's superior bandwidth.

    That author wants you to believe that the P4 will shut down every time you run a application. He wants you to belive that it kicks down to 750Mhz constantly.

    Just another clueless AMD lemming thinking he is smarter than intel engineers.
  27. "I mean, triggering this ACPI event, will it be really 'visible' ?"

    The hardware will notify the OS via ACPI (Advanced Configuration and Power Interface) when this circuit is triggered. The OS can handle this in any way it sees fit, such as displaying a dialog box. Here is a URL documenting ACPI in Windows: http://msdn.microsoft.com/training/offers/WINVBO_BLD/Topics/winvb00132.htm

    "You claim 'maybe one time a year'."

    This is just an average failure rate for when there might be a problem in a cooling solution, such as an extremely hot day coupled with a blocked vent or broken fan, etc. You have the same problems on any system with any CPU. Up until now these merely shortened the lifespan of our CPUs. We were not notified when it happened.

    "Im curious to know if a P4 would stand 70°C without locking up."

    Yes, it would. A P4 can safely operature at up to this temperature without adverse effects.

    "What kind of operations would trigger this maximum power usage"

    This is CPU dependant. Every CPU is designed differently. Generally, the more complex the instruction, the more processing is required to execute it. The more processing that is required, the more circuitry that must be activated within the CPU, and hence the larger the power consumption.


    -- The center of your digital world --
  28. "quotes 1 benchmark where AMD wins from spec.org"

    AMD doesn't win any of those. I don't know what Spec results he's quoting. Take a look at the "SpecInt/SpecFP Intel vs AMD" thread on this board.


    -- The center of your digital world --
  29. Raystonn, After digging around spec.org some more. I have come to the conclusion you are correct sir.

    AMD wins at nothing =)

    Not sure where that goof got those numbers but his link doesnt point to his proof.

    Market researcher? heh. poor reseearching skills let alone his reverse engineering from white papers is truely astounding.

    If your trying to make a point I suggest you not use "I believe" when your trying to be factual. Kinda like assuming and we all know what happens when you assume.
  30. Just a quick comment...
    This was a very polite, informative discussion until fugger & amdmeltdown showed up. Knock it off guys.

    In theory, there is no difference between theory and practice.
    In practice, there is.
  31. Quote:

    poor reseearching skills

    LOL! That sounds funny coming from you. Especially since you claimed there was no such thing as a SMP board for AMD chips, and yet I found over 5 pics in a matter of minutes at google.com. :tongue:

    From now on when someone asks you how fast your computer is, tell them your benchmark scores.
  32. last time I check, I was in america. we have this thing call "freedom of speech"

    So when AMD lemmings give their 2 cents you didnt seem to mind, yet you have the nerve to tell me and meltdown to knock it off. GG

    I post something anti AMD and you get bent.
  33. <<The OS can handle this in any way it sees fit, such as displaying a dialog box>>
    The question remains.. Do Win 9x/NT/2k/Linux do anything with this event ?

    <<Yes, it would. A P4 can safely operature at up to this temperature without adverse effects.>>

    Thats a bold statement to make. I know 70° wont kill the cpu, but im not so sure it would still operate at this temperature. Both my Atlhon and P3 systems will freeze when I get too close to 60°.. The P3 0C-ed to 1 ghz even locks up at 50° (different sort of temp sensor, so actual temperatures on die might be quite different.) Have you ever tested a P4 @ 70°C ??
  34. TOTAL BS

    I have all the engineering docs for the P4,
    and they were misinterpreted..

    the setting was originally made for eventual notebook use,
    and is dependant on ACPI and bios setting for power management,
    and more importantly is a overheating protection mechanism,
    so the chip does not BLOW up like the AMD and burn up..

    in the P3 when is reached this limit of heat or voltage,
    the thing merely shut off,,
    this was not good for smp or servers, so INTEL improved the design so it would scale down ONLY when set or
    when it overheated to the point where it was going to melt
    like the AMD..

    the CPU runs at full speed all the time otherwise
    and I have tested dozens of machines to show this..

    MY P4 1.5 os clocked at 1.6 now and it is running at 32C
    after a benchmark lie SANDRA or Quake hammers it...

    heat is NOT a problem,
    and that design feature and that lame article was misunderstood..

    the point of the overheat diode is not simply to slow down the CPU when the watts get too high, because
    watts do not necessarily equal heat, you can have a CPU at 40 w with crappie cooling run at 70C
    and a CPU running at 80w with great cooling run at 50C..

    the circuit was there to prevent overheating.. so it only slows down the CPU when the CPU reaches over 70C
    otherwise the CPU would MELT like the Athlon Does.. and
    IF the CPU is reaching 70C it is irrespective of the watt or power consumption, but instead shows a cooling problem

    so you can prove this by havint the P4 at the higest watt output yet it WILL NOT THROTTLE DOWN until is reaches the 72C temp overheat..
    YET it can throttle down in DOS with a defective fan
    at only 40W with no load on it at all..

    this proves my point.. the circut is an OVERHEAT alarm,
    NOT a over POWER alarm..

    one does not necessarily relate to the other
    as My CPU overclocked at 1.6 running the toughest benchamrks in the works or a 24 hours burn in test,
    still runs below 35C even though it is at full watt output.

    also the Intel specification was made BEFORE it was decided to use a ATX 2.03 12 v special P4 power supply,
    which takes care of the problem by dedicating a special separate power lead that is discrete just for the CPU..
    separate from the rest of the MB, and it monitors voltage..

    the P4 runs cooler than the 1 ghz P3 and also the AMD by far..

    the article is BS also in that is misleads you into thinking the P4 takes way more power than specified which is crap, because the power supply makers and the design of the special 4 pin power connector have to have an accurate load figure in amps watts and voltage in order to make and engineer a proper power supply,
    as do the MB makers..
    More power does not mean OVERHEATING, it only does in the case like Athlon where the CPU is a thicker DIE,
    older design of ceramic, and inefficient design whereby it requires unreasonable power and cooling

    I talk to INTEL , ASUS , engineers weekly and this is simply NOT TRUE..

    it will and may make more sense when the P4 notebook CPU
    arrives based on the same core as it will have step down technology like this as did P3

    Jesus there are some real meatheads out there

    a little knowledge is a dangerous thing indeed
    <A HREF="http://www.4CyberImage.com " target="_new">http://www.4CyberImage.com </A>
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  35. "The question remains.. Do Win 9x/NT/2k/Linux do anything with this event ?"

    Go visit the link I pasted in that post.

    "Have you ever tested a P4 @ 70°C ??"

    Yes. As the specs say, it operates fine at up to 70C.


    -- The center of your digital world --
  36. the point is the P4 does not get that high unless you leave the fan off in which case unlike the AMD , when it reaches a dangerous overload it will slow down until it reaches a working temp, unlike the P3 which shuts down or locks up,
    or even worse the AMD which merely burns up and
    goes poof


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  37. I understand that much. And I am not trying to make this an AMD vs Intel thread. I dont think anybody with at least some common sense will disagree on this being a good feature, if it works as desribed here.

    But, I just wondered, and still do.. if the P4 can operate at all at this temperature ?I know its "within spec", but Atlhons are spec-ed up to 90°.. I have yet to see the first Atlhon (or any cpu) actually *operate* above 60-65°

    Also..how can a cpu be fried ? I know they can, at least AMD cpus and older pentiums.. but how ? My cpu's lock up long before they reach a critical die temperature (supposedly 90°). When they lock up, I would suspect them not to execute anymore instructions, and sort of cool down automatically ? Or can a "locked-up" cpu be caught in a infite loop ? (sure enough, if you supply them 2v, and run them without a heatsink, they might burn even when iddling)
  38. HI ,
    good questions

    the P4 will operate up to and exactly at spec because tis programmed to slow down when it exceeds it thus making the spec more precise..

    the P3 locks up becasue it has thermal protection that shuts it down when it overheats...
    thus it locks because it is off the OS just does not know this yet :)

    the P4 prevets this by slowing down when it exceeds specs
    until it can still operate effectively thus preventing a lockup...

    this is far superior..
    the AMD to my knowledge has neither and will burn up
    if left on..

    the Pentium 4 is made with a surrounding PCB material similiar to MB material that is a good insulator and is flexible..

    the AMD still uses older ceramic that is brittle and tends to isolate the CPU die and make it hotter without a fan

    I hope that helps


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