CPU frequency always at 3797 MHz

[Shark321]

I have a Windows 7 Pro x64 system used as a home server.
Hardware: Core i5, 4670K (3.4 GHz) on an ASRock Z87E-ITX with the latest UEFI firmware.
I've discovered today that the CPU frequency is too high when the system is doing virtually nothing.
CPU-Z shows a CPU frequency of 3797 MHz. From time to time it drops to 3597 MHz. Multiplier always at 36-38.
Task Manager shows a cpu usage on Core 1 of 5-15%. Other cores are idle. All processes are at 0-1% cpu usage (almost all on 0%).
EIST and all C-States are enabled in the UEFI firmware.
When I change the power profile to power saver the multiplier drops immediately to 8 and the frequency to 799 MHz. But this mode is not an option, as when doing some CPU heavy work like packing using WinRar the frequency is at max 2100 MHz (and usually at 1200), so it's too slow. Additionally the LAN speed goes from about 95 MB /sec to 8 MB /sec (file copy).
If I go back to the Balanced power profile (with default settings) the CPU frequency goes within a second to 3797 MHz and stays there.
I have tried everything besides reinstalling Windows, and still have no idea what causes it.
I hope somebody has the answer why the CPU frequency is so high all the time.

 

[BSim500]

Control Panel -> Power Options -> Change Plan Settings (on Balanced) -> Change Advanced Power Settings -> Processor Power Management, and make sure the following are set to:-

Minimum Processor State = 5%

Maximum Processor State = 100%

 

[Shark321]

This is of course set to 5% and 100%. As stated in the OP the balance profile is to defaults.

 

[BSim500]

This is of course set to 5% and 100%. As stated in the OP the balance profile is to defaults.

What happens if you set it to Power Saver, but then change Power Saver's "Maximum Processor State" to 100% (as above)? Or maybe even create a new custom plan ("Create a Power Plan")? Possible registry entry corruption? Just throwing ideas out there.

 

[Shark321]

Power Saver Maximum Processor state is at 100% by default already. I've tried custom profiles, but when creating one you are asked for the base profile, so the behavior stays the same.

 

[BSim500]

Power Saver Maximum Processor state is at 100% by default already. I've tried custom profiles, but when creating one you are asked for the base profile, so the behavior stays the same.

Does the clock speed vary / show idle in TMonitor or Core Temp (ie, rule out CPU-Z not reading it correctly)? No other overclock / power saver related software running (that came with your motherboard)? BIOS flashed to latest version (or tried reflashing anyway)? No custom multipliers set in BIOS (fine tuned Turbo Boost, etc)? Short of re-installing Windows, I've no idea, as it's weird to have Windows on 100% max yet not demanding more than the second lowest SpeedStep setting under load. Possible faulty motherboard? Is this new behavior or has it been doing it from the start but you've only just noticed?

 

[Shark321]

Core Temp shows the same values. No overclocking software running. Bios (UEFI) is latest version as stated in OP. UEFI is currenctly at default + Power States, but I have tried all options.

I don't think this is a hardware issue, as limiting max cpu state drops the frequency right away. If I set it at 80%, the next second frequency is at around 2400-2600 MHz.

edit:

I've just discovered in Resource Monitor that "System Interrupts" is at 10-15% CPU Usage all the time. On other PCs here "System Interrupts" CPU Usage is at 0%.

 

[ShintaiDK]

it may be due to a driver. Make sure all drivers are updated.

And do you have anything in the PCIe slot?

 

[BSim500]

I don't think this is a hardware issue, as limiting max cpu state drops the frequency right away. If I set it at 80%, the next second frequency is at around 2400-2600 MHz.

Just to go back to something you said earlier:-

"When I change the power profile to power saver the multiplier drops immediately to 8 and the frequency to 799 MHz. But this mode is not an option, as when doing some CPU heavy work like packing using WinRar the frequency is at max 2100 MHz (and usually at 1200), so it's too slow"

Does that happen in apps other than WinRAR, eg, when encoding video or in a Prime stress test? Reason being - on a slow HDD I've seen WinRAR use far less than 100% CPU before (and only "intermediate SpeedStep states"). Try a Prime Stress test and see if it hits 100% on Power Saver (with 100% selected in Maximum Processor State advanced options).

edit: I've just discovered in Resource Monitor that "System Interrupts" is at 10-15% CPU Usage all the time. On other PCs here "System Interrupts" CPU Usage is at 0%.

That does sound high (mine is 0.3% on an i5-3570) and quite possibly a driver issue as ShintaiDK said. Try downloading the latest Intel Chipset drivers for your motherboard. If that doesn't work, make sure every other driver is up to date (SATA, Intel HD GFX, network, etc). Any exclamation marks in Device Manager?

 

[Shark321]

BSim, the system has two fast SSDs.

Found the solution! The culprit was the Intel Graphics driver! I've updated it to the latest version several weeks ago. Uninstalling the driver solved the problem right away (even without a reboot)! I've then installed the old gfx driver offered by Windows Update and the problem remains still solved. 799 MHz at idle with balanced profile!!

 

[BSim500]

BSim, the system has two fast SSDs.

Found the solution! The culprit was the Intel Graphics driver! I've updated it to the latest version several weeks ago. Uninstalling the driver solved the problem right away (even without a reboot)! I've then installed the old gfx driver offered by Windows Update and the problem remains still solved. 799 MHz at idle with balanced profile!!

Aha! Glad you got it working. :thumbsup: