Question My CPU runs OC speeds without OC?

Endre

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Hello! My Intel i7-9700K (3.6GHz, 4.9GHz Turbo) runs at 4600MHz-4800MHz with default BIOS settings! I see these speed values in both BIOS and CPU-Z program.

I’m glad, but how can it be?
 
Well, that's what "Turbo" is for, that's not exactly OC, just running at highest "safe" frequency.
Reason why it's not running at lowest frequency is that OS is doing something requiring more CPU resources. Your Power plan in windows may also influence it, try setting Minimum CPU to 5% or so, at true idle it may even fall under 3.6GHz.
You can see those reasons if you check in Task manager > Performance > Open Resource monitor > CPU.
 
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Karadjgne

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The cpu steps according to load and core usage. Base speed is 3.6GHz. You'll rarely ever see that with turbo enabled because as soon as you get a 25-30% load on the cpu it sets turbo to max performance. You'll get a 40-50% load just opening up any program.

If you only use 1 core working, then turbo will step to 4.9GHz. If 2-3working cores its 4.8GHz, 4-5 cores is 4.7GHz and 6-8 cores is 4.6GHz. The cpu does this to maintain balanced temps across core usage, if turbo is set to lock all cores, you'd see massive heat output at 4.9GHz, basically an OC value
 

boju

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There is also the fact that Intel motherboards typically default to a max boost setting. If you manage to find the "normal" setting for it (it seems only Asus bothered to put one in their BIOSes, and it's not default), your CPU will work at its advertised frequencies and will hold to its "official" power rating (i.e. 95W instead of 150W). If your CPU is well cooled and you don't care about power usage, leave as is. If you'd rather reign it in, either lower your Windows power plan or tinker with your BIOS to prevent the PL2 state from going over the 119W limit and to not last more than 30 seconds.
 

Endre

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The cpu steps according to load and core usage. Base speed is 3.6GHz. You'll rarely ever see that with turbo enabled because as soon as you get a 25-30% load on the cpu it sets turbo to max performance. You'll get a 40-50% load just opening up any program.

If you only use 1 core working, then turbo will step to 4.9GHz. If 2-3working cores its 4.8GHz, 4-5 cores is 4.7GHz and 6-8 cores is 4.6GHz. The cpu does this to maintain balanced temps across core usage, if turbo is set to lock all cores, you'd see massive heat output at 4.9GHz, basically an OC value

The funny thing is that even when I reinstall Windows (clean install) and format C, my BIOS shows CPU frequency as 4700MHz, with default BIOS settings! If I enable Turbo in the BIOS, my CPU will boost frequency at 4900MHz.

I like it, don’t get me wrong, but I’m curious why is this, since is not the Windows power plan that does it.
 

Endre

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Using performance plans will keep your cpu boost frequency higher. Try balance if it bothers you.


If temps are good i wouldn't worry about it. Electricity use would roughly be $50 annually.

No. The temps are fine: between 35-55 celsius degrees.
But I don’t think it’s the Windows power plan that does it, because even when I load BIOS optimal defaults and reinstall Windows (clean) and format partition C, I still see the same CPU frequencies.
 

boju

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Im not sure why in the bios you're still seeing high speeds. Im wondering if c states are temporarily disabled while in the bios to prevent stability of motherboard devices powering down? Hopefully someone else can clarify.

Look for unclewebb's post towards the end on his take what may be happening.


Guessing if that is the case, if power plan in Windows is set to balance with nothing major running does cpu frequency drop?
 

Endre

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Im not sure why in the bios you're still seeing high speeds. Im wondering if c states are temporarily disabled while in the bios to prevent stability of motherboard devices powering down? Hopefully someone else can clarify.

Look for unclewebb's post towards the end on his take what may be happening.


Guessing if that is the case, if power plan in Windows is set to balance with nothing major running does cpu frequency drop?

If I select Windows Balanced power plan. CPU-Z will show my CPU frequencies flickering between 1500MHz-4800MHz, but the BIOS will always show me about 4700MHz even without an OS being installed, and Default BIOS settings.
 

Karadjgne

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It's bios. There is no power plan, no idle, no c-states no nothing. In bios. Bios does not conform to Windows settings for power plans etc because Windows is not loaded, not functional at that point. But it will conform to its own settings, and will run at appropriate speeds for what the cpu is using. There's a difference in what the actual speed of the cpu is currently in bios and what it's capable of.

So when you are in bios, looking at bios values, you get bios regulated settings. When finish booting (bios is an interrupt of the boot process, so holds a certain load temporarily) the pc now responds to the OS values set by the power plan, eco settings or other variable settings.
 
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Endre

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It's bios. There is no power plan, no idle, no c-states no nothing. In bios. Bios does not conform to Windows settings for power plans etc because Windows is not loaded, not functional at that point. But it will conform to its own settings, and will run at appropriate speeds for what the cpu is using. There's a difference in what the actual speed of the cpu is currently in bios and what it's capable of.

So when you are in bios, looking at bios values, you get bios regulated settings. When finish booting (bios is an interrupt of the boot process, so holds a certain load temporarily) the pc now responds to the OS values set by the power plan, eco settings or other variable settings.

Yes. And the BIOS shows not the stock speed of 3600MHz, but 4600MHz-4700MHz. Without any overclock. If I enable OC, the CPU frequency jumps at 4900MHz.
 

Karadjgne

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Because bios is a high load / high core use. You interrupted boot, you didn't stop it. It's still in the boot process. All the cores are engaged, all the cores are being used. That won't stop until windows loads, boot process finishes and eco settings/ power plan settings/ core usage gets applied and Windows is now at idle.