I7 2600k[idle] Changing Multiplier, SpeedStep OFF, Spiking Core

Toms Hardware Forum,

Last Night I noticed something that I'm not sure if its normal or not. I'm just seeking any opinion on the matter, here's the issue:

At first I was overclocking with Intel Speedstep ON, and TurboV ON to a multiplier of 48. It was acting normal, staying at x16 when idle and boosting to x48 when running a game or testing with prime95. 1 Day I started getting really low FPS until I restarted the game and it went back to normal, I didn't like this and I decided to take off speedstep and turboV. I also didn't like how the FPS would jump back and forth as well, and I assume this is from speedstep changing from 1.6ghz to 4.8ghz back and forth, even while the game is open.

I took off SpeedStep and TurboV but kept my other settings of x48 multiplier and 1.4 core voltage. Ram is not overclocked. When I am at my desktop with nothing open except CPU-Z, the multiplier will change constantly from x16 to x48, and it will jump back and forth between the two when the PC is doing nothing, shouldn't this be constant at x48 with speedstep off? I then ran prime95 and it would stay at x48 constant. The thing that is bugging me is this constant changing multiplier when the PC is idle, the CPU usage is moving between 0%-3%, not a biggie, but also I noticed in task manager that the first Core is spiking, not to the top but there are spikes up to about the 30-40% mark, only on the first core. You can see them on the other cores as well but they are really low like 1-5%, and all the HT threads are completely flat.

Is this something that is normal? Do you suggest different settings, for example a friend of mine with a i7 950 has speedstep enabled but turbo off.

The only thing I could think of is that my PSU isn't up to par with the rest of the rig. And maybe the cpu isn't getting enough power to stay at 4.8ghz constant? It's only an Ultra 600w that I elected not to upgrade due to fund issues. I am only using a 4pin connector to the motherboard that has a 8pin cpu power connector.


i7 2600k - Noctua NH-D14
Asus p8p67 deluxe
8gb Corsair Dominator 1600mhz
2x ATI 4850 Crossfire

Thanks in advance for any comments.
6 answers Last reply Best Answer
More about 2600k idle changing multiplier speedstep spiking core
  1. I don't know whether or not the psu is the issue but I would definitely use an 8 pin CPU power cable for that processor, especially with such a high OC....
  2. Thanks for the response. Still looking for more opinions..
  3. Yesterday I just replaced the 600w PSU I had with a Corsair TX850 V2 and I am still experiencing the same issue. Even with turbo and speedstep off the multiplier will change constantly from 16x to 48x(or whatever I have the multiplier set to) even when the pc is idle. It won't stay at 48x constant. Is this just the nature of the sandy bridge or could my bios settings be configured improperly?
  4. Maybe you could try to disable CPU C1E.
  5. Best answer
    While running anything that stresses the CPU, SpeedStep is intelligent enough to keep the processor running at maximum frequency. Your FPS issues aren't due to the processor.

    To completely stop the processor from going into low-power idle mode, you need to disable SpeedStep, C1E, and all CStates settings.

    Check out the Official ASUS P8P67 Series Overclocking Guide and Information for more info.

    Edit: My Sandy Bridge system also spikes from idle mode to full speed every few seconds when I'm not actively using it. This is normal behavior, as different things are going on in the background that we are unaware of.
  6. Best answer selected by sslazio77.
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