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Windows 7: Why does my core speed up at idle?

11 Mar 2013   #1

Windows 7 Pro 64bit
Can you help me determine if CPU-Z is giving me false readings?

I'm starting to do some overclocking with my core i5 750 and ASUS P7P557D Pro according to THIS TUTORIAL

So far I set the DDR3 frequency to 1600 and increased the BCLK frequency to 144MHz.

The weird thing is that when I run CPU-Z and watch it while running Prime95 to stress the system the core speed is faster when at idle. As soon as Prime95 starts, it slows down.

Here is the CPU-Z at stress:

Here is CPU-Z at idle:

I don't understand?

Shouldn't the core slow down at idle?

My System SpecsSystem Spec
11 Mar 2013   #2

Windows 7 Pro 64bit

Also, CoreTemp is giving me a different read.

Here it is at the same frequency running the Prim95 Test. CPU-Z displays as above, CoreTemp displays like this:

Am I using these programs incorrectly?
My System SpecsSystem Spec
16 Mar 2013   #3

Windows 10 Pro (x64)

When stressing all cores on the CPU the turbo only goes so high on all four cores. However when you only have one core being utilized with any load it will go much faster. That is how Turbo Boost works.

And there is no such thing as idle. You may be idle but the computer rarely is.
My System SpecsSystem Spec


 Why does my core speed up at idle?

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