XMP Profile and Processor Frequency (Ai Overclock Tuner: XMP vs Auto)

[MayuraDeSilva]

Hello,

Today I've upgraded my CPU to i5-3470 from i3-3210, and noticed strange clock speeds (idle) with XMP profile enabled.

I have an ASUS motherboard and the problem is if I enable XMP profile in BIOS (via Ai Overclock Tuner), my idle clock speeds stay over 3.2GHz most of the time. It goes down to 1.6GHz too, but goes back to 3.4GHz or so.

Then I set the Ai Overclock Tuner to AUTO and manually set the Memory Frequency to 1600MHz. From that point onwards, the idle clocks stays at 1595MHz.

I read the description for XMP mode in BIOS, and it depicts that XMP mode affects CPU ratio and BCLK frequency. But since I had Enhanced Intel SpeedStep Technology enabled in BIOS, thought processor frequency may adjust dynamically to decrease the power and heat production.

So if I have XMP profile selected, SpeedStep won't be active? and clock speeds will optimize based on the Memory frequency even in the idle states?

Can't recall observing this difference with i3 though - had XMP profile enabled with i3 too.

CPU: Intel Core i5-3470 3.2GHz
Motherboard: ASUS P8B75-V
Memory: G.SKILL RipjawsX 16GB (2x8GB) 1600 DC

Thanks.

 

[vijenderrinku]

"It goes down to 1.6GHz too, but goes back to 3.4GHz or so." it means CPU in power save mode. when system in Idel it goes to 1.6 GHz and when load in CPU , it goes to 3.4 GHz.
this is all about Power Saving. if your want that CPU ran at 3.4GHz always. The core parking must be 100. this can be done with CORE PARKING Manager.

"the idle clocks stays at 1595MHz."
approximate frequency which is near to 1600 MHz. so it not issue. it is common

For best result, set to all setting to Manual.

 

[MayuraDeSilva]

"It goes down to 1.6GHz too, but goes back to 3.4GHz or so." - In this case with XMP enabled, the clock sets to 1.6GHz momentarily in idle state. Then most of the time it's between 3.2GHz - 3.4GHz. This is not in load. Just in idle state.

But with AUTO configuration, the idle clocks stays at 1595MHz. Sticking to it right now and clock speed fluctuate accordingly while DRAM frequency is 800MHz

 

[MayuraDeSilva]

So... The XMP profile gonna affect CPU frequency and keep it optimized based on the DRAM frequency? - activating TurboBoost and ignoring SpeedStep?

 

[MayuraDeSilva]

After tweaking and experimenting with some settings, I found that the Minimum processor state was set to 100% in my High Performance power profile. Set it to 5% (Default value in Balanced profile).

Then set the XMP profile again in BIOS and immediately, I can see the clock speeds are fluctuating and keeping to 1599MHz in idle state. Not running at 3.4GHz all the time.

Still I'm interested to know if there's any way to verify if the Intel SpeedStep is active right now. Or is it the Windows power profile did this?