SPCR

My current main system is a Phenom II X4 955 and with that, at idle the CPU will generally stay at 800Mhz whilst the CPU is below 25% and even then very brief spikes won't cause it to increase.

I've just built a Asus Z97-A/i5 4670k system (OC'd to [email protected]) and with this, cores 2&3 seem to spend most of the time around 1400-1700Mhz, in fact core 1 has joined in now, so only core 0 seems to mostly stay at 800mhz, even though the CPU usage is below about 8% and the cores below about 10%. I've also noticed the core VIDs and Vcores stay at fixed voltages, unlike my AMD system where they decrease at lower clocks to save energy and reduce heat.





I'm sure I'm overlooking some BIOS setting due to being an Intel noob but is there a way to make the CPU step up less aggressively and also reduce the VID/Vcore when running at below full speed?

In the BIOS, look to see if:

Enhanced Intel Speed Step (EIST) is enabled.
Intel C-State is enabled.

There are also some halt-state power saving features that can be enabled.

It'd be funny if your hardware monitor app was the reason the CPU spins up .

SpeedStep, Turbo Mode and CPU C-States are enabled (C-States was on Auto, so I've changed it to Enabled but it hasn't made any difference).

It has a setting 'Package C-States Support' which is set to Auto and has various options (Enabled, C0/C1 - C7, C7s), so maybe that needs to be set to something else?

I don't think HwInfo can be causing the problem as it doesn't with my AMD system and it's not causing any noticeable CPU activity anyway.

I tried setting the 'C-State' Package setting to C7 (or C7s I'm not sure) but then I got a corrupted screen and locked-up PC when I next woke the monitor (PC wasn't in standby) so I've put that back to Auto. In fact, I reset the BIOS to default settings and like that, with no overclock, the VID and Vcore properly adjust along with the CPU speed, although it still keeps flipping into higher states despite the CPU basically idling and with no correlation between core usage and higher states, as core #0 here is at 5.4% but 800Mhz, whilst cores 3-4 are at 2.7% and 1500Mhz



So hopefully there's a way to make it change the Vcore and VID automatically when overclocking as well.