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What is thermal throttling?

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Jul 8, 2004
While looking through my BIOS i saw this entry? (im a newbie to OC'ing and hardware details btw). Mine is currently set at 50% - what does this setting do and what is a good setting?

MOBO = Abit AN7
Processor = barton 3000
yes i notice this in my bios to but i had gotten told to just disable it i am not sure if this is right or not.
Thermal throttling is when the CPU overheats, the mobo sets its speed lower, so it can generate less heat and cool down.
Clock Throttle

Common Options : 12.5%, 25.0%, 37.5%, 50.0%, 62.5%, 75.0%, 87.5%

Quick Review

This BIOS feature allows manual configuration of the Thermal Control Circuit. Instead of allowing the TCC to automatically start with a duty cycle of 30-50%, you can manually set the duty cycle.
Available options for this BIOS feature are set values of the processor's duty cycle when the Thermal Control Circuit gets activated. They range from a low of 12.5% to a high of 87.5%. Please note that these options reflect the processor's duty cycle, not its clock speed. The clock speed of the processor remains unchanged.

If you are looking for a Disabled option, there is no such option. You cannot turn off the Thermal Control Circuit. But if you keep your processor cool enough so that it never exceeds the maximum safe operating temperature, the Thermal Control Circuit will never get activated.

The default setting is usually 62.5%. This means the Thermal Control Circuit will insert null cycles to allow the processor to "rest" 37.5% of the time.

The choice of what you should set the Thermal Control Circuit to run at is really up to you. The lower the duty cycle, the slower your processor will perform but it will take less time to cool down the processor enough to turn off the TCC. Using a higher duty cycle will not impair performance as much but it will take longer for your processor to cool down enough to turn off the TCC.


* This site has the answer to every setting in the bios..Save this one! ;)
That explaination of clock throttling is for P4s. They will throttle down the speed if they get too hot. The type of thermal throttling for AMDs is totally different. It means when the computer goes into low-power mode (sleep mode) it will slow down the CPU to save energy. The slower it goes the longer it takes to get out of sleep mode.

EDIT: Hold on, I may be wrong let me do some research.
Yea but that's about a A64 processor. Let me see if I can find the site where I got the info from before.

EDIT: Well I must have been thinking of some other setting. You're right.
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From what I understand, the athlon thermal-throttling is very much like the thermal-throttling built into notebook processors. As the processor approaches a specified temperature, the clock speed is reduced to lower the dissipated wattage of the processor, which in turn lowers the heat output of the processor. This may be incorrect, I have never actually used/seen this feature in action because the thermal limits of athlons are so high that I don't believe many systems actually every have to utilize this function.

As far as I know, the P4 thermal-throttling actually does the same thing as the athlon's does, except the P4's is handled automatically by the on-die sensor, whereas the athlon's is controlled differently. I believe that the thermal-throttling that the RojackPot was refering to us an older solution to the problem - it is not a perfect guide, however, it is a damn good one :) - props to you archi for the link!

Not saying that I am right and everyone else is wrong, but from what I've read, that seems to be the way things work. I am not so sure about the P4 technique (Intel uses a TON of tricks in it's CPUs), but I am confident that the Athlon explanation is correct.
I have an DFI lanparty B mobo.

a AMD XP mobile 2600+

my mobo's bios comes with the option of thermal-throtting. i can chose any of those choices, also i can disable it.

but thats the joy of owning an AMD.....and a DFI mobo.
Interesting, this is a learning process for me too..It's not worth getting up in the morning if I don't learn something new that day..;)