Intel Core Duo T2400 clock speed steps down


I know this is a really old processor, but I'm wondering if anyone has any idea why my T2400 reduces its clock speed when I'm doing things on my computer. A lot of times I'm just streaming a video from Youtube or I'm trying to watch a 720p movie and it starts to lag and my CPU goes to 100%. I check the properties and it shows something like 987Mhz as opposed to 1.83Ghz at full speed. Because I'm using the CPU, isn't SpeedStep supposed to keep the clock speed high instead of stepping it down?

Does anyone know why this is happening? After a few minutes of idling (e.g. stopping playback), the speed goes back up to 1.83 Ghz. I'm totally confused by this behaviour and it's pretty annoying. Hope someone can help me out.

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More about intel core t2400 clock speed steps down
  1. Please check ur CPU speeds using CPU-Z...a small free software:) My computer Properties isn't very accurate and doesn't give u continuous real time CPU speed:)
  2. Ok, so I've downloaded CPU-Z as well as RealTemp. RealTemp is showing 997.50MHz. CPU-Z shows Core Speed of ~1830 MHz and the Core VID goes down to 0.950V. Multiplier is x6.0 for both. I think RealTemp has the right clock speed. So it looks like the CPU starts to step down after it hits a temp of 73C. Is this normal?

    If this is indeed a heat issue and my laptop is 6 years old, what should I do to remedy it?
  3. Realtemp 3.00 I use is anything but accurate!!! Don't know about the newer versions. Realtemp probably just copies the value form My computer!!

    CPU-z is the most accurate always. Only refer to CPU-z's readings. If CPU-Z shows 1.83, its 1.83GHz. Period. Ur CPU is perfectly fine like i thot it wud be :)

    FYI x6.0 is the lowest possible multiplier for all Core2Duo chips :)
  4. But if my multiplier is at x6.0, doesn't that mean my clock speed has slowed down? At x6.0, 997.50MHz is correct. Along with this step down in multiplier, the computer slows down considerably. I'm using RealTemp 3.70 btw. This clock speed is also reported by RMClock.

    Using RMClock, I am able to lock the multiplier at x11.0, which is max. However, the multiplier seems to fluctuate between x10.0 and x11.0 with all the decimal values in between. For some reason it can't hold it steady. After a while, the lag returns. I'd like to know why.
  5. the CPU will drop to x6 ONLY if there is no work for it to soon as a significant load is encountered, it will automatically increase the multiplier by as much as is required.....i think the only possible deviation from this normal behavior occurs if the CPU is extremely hot due to overheating.

    FYI multipliers are only integer values...some support half multipliers, but i'm not sure urs does, so 6.0,6.5,7.0,7.5 etc are the only possible values....if ur seeing somethin like 10.3 thats probably the result of the software averaging the multipliers over a period of time. Like i said before....CPUz is the only accurate real time speed indicator that i know of.

    The reason for ur lagging lies elsewhere, it is not ur CPU:)
  6. Did you set it to High performance?
  7. It seems that CPU starts stepping down to x6.0 once the 73C threshold is hit. I can lock it at x11.0 with RMClock and the clock speed doesn't step down anymore. Unfortunately, performance still degrades. Maybe it's the GPU? My GPU (ATI X1400) has temps of around 78-80C. Memory is at 75C, Chipset is 61C.

    Do those temps look normal?
  8. Your GPU and chipset temperatures are fine:) Is thatCPU temp of 73C Tcase or Tjunc ??
    Memory temps i have no idea....but i guess 75C is kinda OK using my common sense :)

    Na...i guess its just a simple software cud possibly be a virus:) Some program is hogging up the CPU and causing the slow down, its not GPU related. I think u shud take a closer look inside Task Manager :)
  9. Chrome hogs up most of the CPU when I'm browsing and streaming video. Other than that, it's AVG an sometimes ZoneAlarm. That's the thing though, I know there's stuff using he CPU and at full clock, performance is fine. Once it steps down though, there's not enough clock to go around and performance suffers greatly.

    I just don't get why it's stepping down when I consistently have high load. It's counter-intuitive and this is the reason behind this thread.
  10. Are u running XP or windows7? I can tell u a way to make your chip run like a desktop chip, so that performance is given the main priority....the downside is that the battery will drain faster, and the lappy mite get a bit hotter:)
  11. Running XP. The laptop is already 6 years old so no battery left. I basically use it as a desktop.
  12. Perform the first 5 steps as mentioned in this site,

    Set the type of computer to Home desktop instead of laptop.....i'm currently running Win7 so don't remember exactly what it was called.....but u'll find it :)
  13. Thasks $hawn, I've always used Always On as my Power Profile already so it's not that.
  14. k is it same as the Home/Office desk setting?
    Sorry, m outta idea's:)
  15. Yup, it's the same. Thanks for trying. Anyone else have any ideas why it's stepping down when I need CPU the most?
  16. Hi Cobra,

    I registered just to share some intel with you.

    It seems that C2D processors are designed to throttle the clock speed down to a half when no battery is present. It was definitely present in Apple laptops, but I've read elsewhere a comment that said this:

    I think it should be mentioned though that removing the battery reduces the maximum CPU speed by half. This is a characteristic of most modern laptops. The power brick and battery are part of an integrated power supply system, and when the battery is not doing its part, the CPU is throttled back.
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