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How much does P4 slow down with thermal protection?

By Mictlantecuhtli
Mar 25, 2002
  1. Does anyone have information about this? Or should I just test?
    I began thinking about this last night when my computer started to feel sluggish. I was using BeOS, Seti@Home running in background, listening to music, copying files when I realized that windows are resizing & moving slower than usual. Then I checked my CPU temperature - 82C! Looked into the case - CPU fan had shut down. Now if I had a realtime CPU speed monitor, I could make a chart about how much temperature affects speed. I'd say it was something like 200-300 MHz, it felt like that.
     
  2. Didou

    Didou Bowtie extraordinair! Posts: 5,899

    I think it depends on the settings in your BIOS.

    There's a first option that says which action to take in case of overheat : ShutDown / Throttle

    You should be able to find another option stating how much to throttle ( in case you choose to do so instead of ShutDown ).
     
  3. svtcobra

    svtcobra TechSpot Paladin Posts: 875

    Wow Mic...82C! My T-Bird would be in a grave right now and my credit card would be about 200 bucks heavier after the purchase of a new CPU. That thermal protection works very well on the Intel processor. Im sorry I dont have an answer to your question, I just wanted to comment on your situation.
     
  4. Mictlantecuhtli

    Mictlantecuhtli TS Evangelist Topic Starter Posts: 4,919   +9

    Hmm, I haven't seen anything like that in this BIOS. My motherboard is Soltek 85SD-C. There is this SmartDoc Anti-Burning Shield but I've disabled it. It just nags if temperature is too high (well, I haven't seen it doing anything else).
     
  5. Mictlantecuhtli

    Mictlantecuhtli TS Evangelist Topic Starter Posts: 4,919   +9

    Ok, I found what I was looking for:
    Intel Pentium 4 Processor in the 478-Pin Package at 1.40 GHz, 1.50 GHz, 1.60 GHz, 1.70 GHz, 1.80 GHz, 1.90 GHz and 2 GHz Datasheet
    Note: TCC = Thermal Control Circuit, timeframe in Table 16 = 0.5 seconds
    So, as ACPI is disabled, I assume automatic mode is enabled but yet I found it hard to believe my PC was running @ 50% speed.

    Edit: sorry, wrong link, it's fixed now
     
  6. T-Shirt

    T-Shirt TS Rookie Posts: 329

    By design P4 thermal protectection will continue to slow down the processor, until thermal balance is met (temp rise stops) if this cannot be achived, if overheat continues it will turn off the processor before damage occurs. The settings in the bios do not control the degree of slowdown, thats based on tempature, they do allow you to set how soon before overheat slowdown begins.
     
  7. T-Shirt

    T-Shirt TS Rookie Posts: 329

    But if it was a borderline overheat it may have been cycling back and forth between 50-100% many times a second. from your time scale several seconds at a time, the average speed may have been in the 75-90% range you perceived. I was work exactly as designed:grinthumb
    It does mean you need to think about addtional cooling.
     
  8. Mictlantecuhtli

    Mictlantecuhtli TS Evangelist Topic Starter Posts: 4,919   +9

  9. Mictlantecuhtli

    Mictlantecuhtli TS Evangelist Topic Starter Posts: 4,919   +9

    Now that P4 speeds have passed 3 GHz, I decided to do a little research on this again.

    First of all, I assume some, if not most, of you have heard of / seen Tom's Hardware Guide's video where they take the heatsink off of a P4 and it continues working, just slows down. Then they put the heatsink back and it speeds up quickly again.

    As this test was done with Socket 423 CPU using i850 motherboard - Asus P4T - the question is:

    Does this still apply for new P4s?

    Some time ago when I had P4 1.6, I tried booting without heatsink at all. I got to BIOS, checked CPU temperature, which then went off scale quite quickly, and the system just froze. I put the heatsink back but it didn't help, I had to hit reset button.

    With high clock speeds, could it be that the CPU can't slow down quickly enough? What I find weird is my CPU was 1.6 GHz and the CPU tested on Tom's video was 2.0.

    Any thoughts? Anyone else willing to test? (I dare you :p)
     
  10. Nic

    Nic TechSpot Paladin Posts: 1,928

  11. Lol, if you wanna keep your computer cool, maybe you been overclocking, dunno, but have a look at this company, they make water cooled cases, awesome! http://www.koolance.com
     
     
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