Need help reaching Package C8 on Intel N100

[tmkhiem]

Hi! I just bought a N100 laptop and performed a clean Windows 10 Installation on it. Since I will be using the machine for on the go working, after installing all drivers, I proceed to download ThrottleStop to optimize the battery usage. However, I'm at my wit's end because I have tried everything that I know (there is a list of them below) but no matter what I do, I cannot achieve package states deeper than C3.

Laptop's specification:

• Manufacturer: CHUWI
• Intel N100 Alder Lake
• LPDDR5 16GB 4800MHz soldered on
• 512GB AirDisk SSD
• BIOS: AMI
• LAN NIC: Internal Realtek USB FE
• WLAN NIC: Intel AX101

As with most noname manufacturers out there, I got almost every setting imaginable available for tuning. Almost nothing is hidden away. I could configure FIVR in the BIOS but whether it is effective is an another story, however I could see that disabling CFG lock in BIOS did reflect in ThrottleStop (no more "C States Locked").

Software specification:

• Windows 10 Home 22H2
• ThrottleStop 9.6
• Timer resolution in "Options" 15.62, a "relaxed" value I believe.
• powercfg /energy returns no error and some minor warnings.

What I have tried:

• Disabling the Internal Realtek LAN NIC. I also have an another laptop (i7-8550U) that only reaches PC8 with latest Realtek drivers. I tried updating the Internal NIC but it didn't work this time. Also

  powercfg /energy

  reported that it cannot do selective suspend and with it being a 100M only NIC I disabled the USB port altogether.
• Updating the Microsoft AHCI driver to "Intel 500 Series chipset AHCI controller". I have read somewhere that MS default AHCI drivers will prevent the system from going deeper than PC3 but still no luck. I know that Alder Lake would be equivalent to 600 series chipset but I can't find the AHCI drivers for 600 series anywhere.
• Followed this post on modifying relevant BIOS settings. I don't need to use the mentioned tool (AMISCE) because they're all available . But didn't work.
• Manually forcing DMI ASPM, SA PCIE ASPM and PCH PCIE ASPM to Auto, L1 and L0sL1. Both without success. I'm leaving it at L1.
• Manually entering C6/C7, C8, C9 and C10 Latency values that I copied from another system. My theory is that it's possible that a zero value may have somehow disabled the C state. It seems not to be the case, though.
• Enabled S0i2.0 and S0i3.0 -- no changes. From what I gather, they are supposed to be the "new sleeping" standard in place of S3 so I figured they might have something to do with low power.
• Turning on Speed Shift + EPP since it is disabled the first time I open ThrottleStop. I'm not sure if this matters with AlderLake.

What's weird:

• Apparently, there could be some BIOS settings that will render other settings ineffective (i.e. will be of no function without being grayed out). I tried limiting maximum Package C State to C2 and C1 but both ThrottleStop and HWINFO still shows some PC3 residency. However, some other tinkering around results in PC3 and PC2 not getting any altogether so I thought my current BIOS setting is as good as I can get.
• Right now both core C6 and C7 are at over 90%. I don't think this is possible because I think the sum of one core's C3%, C6% and C7% should not exceed 100% (Did I understand it right?). This is verified with MSR reading at 0x000003FD (CC6) of 00000020:2D553138 and reading at 0x000003FE (CC7) of 0000001F:5AE1F26F, while 0x000003F9 (PC6), 0x000003fa (PC7) and deeper states return all zeros.
• "C-State auto demotion" and "C-State undemotion" has only two possible values: Disabled and C1. Selecting C1 results in ThrottleStop showing "C1" button instead of "C9" but inside ThrottleStop's C States window still shows C9.
• In some combination of BIOS settings (I did not do a great job at keeping track of which settings has what value partly due to the vast amount of settings), requesting C7 will prevent Package C3 but allows Package C2.
• In some other combinations, like what I'm having currently, requesting C1 does not have any effect at all. The package still reaches C3.

Attached are some screenshots of ThrottleStop. Due to the vast amount of configurable settings in the BIOS I could not show them all here, and some of them have been changed, but any help would be appreciated!

EDIT: Added some logs.

 

[unclewebb]

both core C6 and C7 are at over 90%. I don't think this is possible

I agree. On most Intel CPUs, the sum of the individual core C states as reported in ThrottleStop does not exceed 100%. The values in the C6% column of the ThrottleStop C state monitoring table are all higher than the C7% column. Whatever is being reported in the C6% column might be multiple different C states including C7%. I have never owned or had access to an Intel N100 CPU for testing purposes. How well ThrottleStop works on the N100 is unknown. There might be bugs like the C state bug you found.

On my 10th Gen desktop CPU, I have never made it beyond package C3. It might be a driver that blocks the deeper package C states. I gave up trying to figure out why. On a desktop CPU, a tiny amount of idle power is not worth chasing after. Hopefully you can find a way to unlock the package C state mystery. Lots of laptop owners could use some extra battery run time.