@captain-j I agree, it's puzzling! Whatever I try, I can't seem to get my cores to drop below that 2,68 Ghz.
I have experimented with various options:
- Enabling/disabling EIST doesn't seem to alter my frequencies.
- I overclock by upping the turbo frequencies on all cores to 4.5 Ghz. Disabling the overclock doesn't seem to alter the frequencies when idling. Output looks about the same.
- I alternately ran that SSDT for plugin-type from OP and a SSDT generated with the ssdtPRGen script by Piker-Alpha. Frequencies again seem to be the same with whatever SSDT I use.
Good suggestion about measuring power consumption. I have a wattmeter lying around, so I connected it to my system and took it for a spin. I don't know how accurate it is absolutely speaking, but at least I can compare different settings. Here are the results after I let my system idling for a couple of minutes:
- Using Injector with HWP and SSDT for plugin-type: ~80 watt
- Using injector with HWP and SSDT generated with ssdtPRGen: ~80 watt
- No SSDT (and no X86PlatformPlugin but seemingly correct frequencies): ~77 watt
Using no SSDT seems to be a bit more efficient, but a lot less than I would've expected. Maybe the upped efficiency of the CPU is largely negated by the loss of other power saving functions provided by the X86PlatformPlugin that isn't loading. It's hard to say.
Also interesting: I additionaly have Windows 10 running on my system, so I checked power consumption over there. I measured ~54 watt after idling for a couple of minutes. A pretty big difference.