Fluctuating CPU Frequency

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sArge_sF

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Hi

So, as some may know from my previous thread, I upgraded to a 2600K.

I haven't overclocked anything yet and my motherboard hasn't got any performance boosters enabled, however, I notice that the Frequency of the processor fluctuates between 1.5 Ghz and 3.8 Ghz when the PC is idle..

As far as I know, this processor has a built in Turbo feature which controls that? Correct me if I'm wrong.

The real question is, is this rate of fluctuation normal? Apparently this Turbo feature can also disable cores for some kind of performance boost?

Thanks
 
Yes, that's normal. If you change set the Windows power scheme to anything other than maximum performance, the CPU frequency will be scaled when it's idle. My Core 2 Duo E6320 fluctuates between 900 MHz (I think) and 1.87 GHz, depending on the load.
 
sArge_sF said:
Hi

So, as some may know from my previous thread, I upgraded to a 2600K.

I haven't overclocked anything yet and my motherboard hasn't got any performance boosters enabled, however, I notice that the Frequency of the processor fluctuates between 1.5 Ghz and 3.8 Ghz when the PC is idle..

As far as I know, this processor has a built in Turbo feature which controls that? Correct me if I'm wrong.

The real question is, is this rate of fluctuation normal? Apparently this Turbo feature can also disable cores for some kind of performance boost?

Thanks
Click to expand...

It's called Cool'n Quiet or Speedstep. All new CPUs do it.
 
I don't recommend it, the CPU ramps up in a fraction of a second and saves you a ton of power by down clocking when not under load.
 
Shayd said:
I don't recommend it, the CPU ramps up in a fraction of a second and saves you a ton of power by down clocking when not under load.
Click to expand...

Are you disagreeing that is Cool 'n quiet should be disabled?
 
sArge_sF said:
Hi

So, as some may know from my previous thread, I upgraded to a 2600K.

I haven't overclocked anything yet and my motherboard hasn't got any performance boosters enabled, however, I notice that the Frequency of the processor fluctuates between 1.5 Ghz and 3.8 Ghz when the PC is idle..

As far as I know, this processor has a built in Turbo feature which controls that? Correct me if I'm wrong.

The real question is, is this rate of fluctuation normal? Apparently this Turbo feature can also disable cores for some kind of performance boost?

Thanks
Click to expand...

It's actually pretty awesome that it does underclock when it doesn't require the power.

Not only does the CPU cool down a fair bit, it also saves a fair amount of power. I have a 2500k and even while watching media/using a virtual machine, it sits at 1.5GHz and it's still fast enough to do everything at speed.
 
sArge_sF said:
Are you disagreeing that is Cool 'n quiet should be disabled?
Click to expand...

Leave the cool n quiet or speed step technology disabled. The PC is meant to run with out enabled and having the PC run full ball while you watch YouTube or type emails is just going to result in higher electrical bills, more noise and more PC dust. I don't see any benefit, do you?
 
froot said:
It's actually pretty awesome that it does underclock when it doesn't require the power.

Not only does the CPU cool down a fair bit, it also saves a fair amount of power. I have a 2500k and even while watching media/using a virtual machine, it sits at 1.5GHz and it's still fast enough to do everything at speed.
Click to expand...

Even though I disabled SpeedStep, C1E and Turbo Boost in my Bios, CPUZ still shows the frequency at 1.6Ghz when the PC is idle..

Any ideas?

One more thing, the AI Suit that comes with Asus Motherboards - is its CPU temperature sensor reliable? I ask this because when I access my BIOS, the CPU temperature reads about 50 - 60 degrees Celsius, but when I boot into Windows, the Asus software says its at 37 degrees Celsius..
 
Speed Step and automatic CPU voltage makes a huge difference in the power consumption.

P = f * k1 * (V^2), where f is your CPU frequency and V is your CPU voltage. k1 is just a constant for your CPU.
So by reducing your CPU frequency from like 3GHz to 1.5GHz (and keeping the voltage fixed) would already reduce the power consumption by 50%. Changing the voltage just slightly has a massive effect too.

Technically speaking, this is the dynamic power consumption part - and you also get a static power consumption part: P = k2 * (V^2)
So doubling the frequency won't really double the power consumption, since the static power consumption part remained the same.
 
Pada said:
Speed Step and automatic CPU voltage makes a huge difference in the power consumption.

P = f * k1 * (V^2), where f is your CPU frequency and V is your CPU voltage. k1 is just a constant for your CPU.
So by reducing your CPU frequency from like 3GHz to 1.5GHz (and keeping the voltage fixed) would already reduce the power consumption by 50%. Changing the voltage just slightly has a massive effect too.

Technically speaking, this is the dynamic power consumption part - and you also get a static power consumption part: P = k2 * (V^2)
So doubling the frequency won't really double the power consumption, since the static power consumption part remained the same.
Click to expand...

I understand that quite a bit of power is saved, but I do have an issue where I am unable to actually disable this feature.

As I said, I disabled SpeedStep, C1E and Turbo Boost yet the processor still underclocks and lowers voltage to 0.9V when the PC is idle.
 
Did you install any Asus EPU/AI suite software? I'd recommend that you uninstall that crap.

My i7 860 + Asus P7H55D-M Evo is incredibly unstable with the Asus EPU software, because it underclocks and undervolt the CPU too much when it is idling.
Enabling Speed Step and setting the voltage to auto works so much better than using the Asus EPU crap.
 
Pada said:
Did you install any Asus EPU/AI suite software? I'd recommend that you uninstall that crap.

My i7 860 + Asus P7H55D-M Evo is incredibly unstable with the Asus EPU software, because it underclocks and undervolt the CPU too much when it is idling.
Enabling Speed Step and setting the voltage to auto works so much better than using the Asus EPU crap.
Click to expand...

Does Asus AI actually change voltages and clocks even when Auto tuning is not enabled?
 
sArge_sF said:
Does Asus AI actually change voltages and clocks even when Auto tuning is not enabled?
Click to expand...
I don't think the AI Suite worries about what the settings in the BIOS are. AI Suite has a few profiles, in which you set how much the voltage/frequencies should be boosted/decreased.

I haven't used it in a long time, so I might be wrong here.
 
From all the overclocking guides ive seen, even they recommend leaving speed step and all that stuffs on...
You are able to control your clocks and voltages, for the overclocked, under load state. but when the cpu isnt loaded, it underclocks to a default value, which is simply a lower multiplier.

w.r.t asus ai, I wouldnt trust the values they report... I often have warnings popping up of my 3.3v dropping to 0 and my motherboard temp dropping to -126 degrees :wtf:
 
evovil said:
From all the overclocking guides ive seen, even they recommend leaving speed step and all that stuffs on...
You are able to control your clocks and voltages, for the overclocked, under load state. but when the cpu isnt loaded, it underclocks to a default value, which is simply a lower multiplier.

w.r.t asus ai, I wouldnt trust the values they report... I often have warnings popping up of my 3.3v dropping to 0 and my motherboard temp dropping to -126 degrees :wtf:
Click to expand...

Is there any reliable sensor software that works well with Asus?
 
sArge_sF said:
Is there any reliable sensor software that works well with Asus?
Click to expand...
I use HWMonitor from CPUID and so far it seemed to work very well. But then again, I haven't had any sensor issues with the Asus software either.
 
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