You seem to have gotten one step further. Just some thoughts.
Does grep . /sys/devices/system/cpu/cpu0/cpuidle/state*/namestill show ACPI states ?

(I somehow don't have pmc_core on ubuntu)
Did you confirm Low Power S0 Idle (V5) : 1 in the dumped ACPI tables?

Does your board have a beta firmware from ASROCK? The Z890 boards seem to have one.

1 hour ago, JanTenner said:

You seem to have gotten one step further. Just some thoughts.
Does grep . /sys/devices/system/cpu/cpu0/cpuidle/state*/namestill show ACPI states ?

(I somehow don't have pmc_core on ubuntu)
Did you confirm Low Power S0 Idle (V5) : 1 in the dumped ACPI tables?

Does your board have a beta firmware from ASROCK? The Z890 boards seem to have one.

Yet again, intel is too lazy to fix intel_idle so all working c-states are just dumped into three. 13th gen did the same thing at first.

grep . /sys/devices/system/cpu/cpu0/cpuidle/state*/name

/sys/devices/system/cpu/cpu0/cpuidle/state0/name:POLL

/sys/devices/system/cpu/cpu0/cpuidle/state1/name:C1_ACPI

/sys/devices/system/cpu/cpu0/cpuidle/state2/name:C2_ACPI

/sys/devices/system/cpu/cpu0/cpuidle/state3/name:C3_ACPI

AFAIK, there are zero arrow lake boards that have S0ix enabled through bios or via a beta bios. Mine is "0" i.e. disabled.

I have an Asus board and there is no way to talk to asus engineers to even get S0ix enabled.

Anyone on arrow lake getting these errors in the syslog I'm using a w880 Asus

Nov 5 19:43:54 AdziUnraid kernel: pcieport 0000:00:06.1: AER: Correctable error message received from 0000:00:06.1

Nov 5 19:43:54 AdziUnraid kernel: pcieport 0000:00:06.1: PCIe Bus Error: severity=Correctable, type=Physical Layer, (Receiver ID)

Nov 5 19:43:54 AdziUnraid kernel: pcieport 0000:00:06.1: device [8086:7e

5 hours ago, Solarisfps said:

Anyone on arrow lake getting these errors in the syslog I'm using a w880 Asus

I have the Asus Pro WS Z890-ACE SE running 7.2.0 and I don't see any errors like that in my my syslog. I only see these:

Nov  5 19:21:47 Megamind root: error log : /var/log/graphql-api.log
Nov  5 19:22:09 Megamind kernel: ACPI BIOS Error (bug): Failure creating named object [\_SB.PC00.RP01.PXSX._DSM.USRG], AE_ALREADY_EXISTS (20240827/dsfield-184)

As a side note how are you liking the w880? That was one was my second choice but wanted the 10G NIC.

Edited November 6, 2025Nov 6 by kimocal

6 hours ago, kimocal said:

I have the Asus Pro WS Z890-ACE SE running 7.2.0 and I don't see any errors like that in my my syslog. I only see these:

Nov  5 19:21:47 Megamind root: error log : /var/log/graphql-api.log
Nov  5 19:22:09 Megamind kernel: ACPI BIOS Error (bug): Failure creating named object [\_SB.PC00.RP01.PXSX._DSM.USRG], AE_ALREADY_EXISTS (20240827/dsfield-184)

As a side note how are you liking the w880? That was one was my second choice but wanted the 10G NIC.

Apparently for my error this will fix it

6 hours ago, kimocal said:

I have the Asus Pro WS Z890-ACE SE running 7.2.0 and I don't see any errors like that in my my syslog. I only see these:

Nov  5 19:21:47 Megamind root: error log : /var/log/graphql-api.log
Nov  5 19:22:09 Megamind kernel: ACPI BIOS Error (bug): Failure creating named object [\_SB.PC00.RP01.PXSX._DSM.USRG], AE_ALREADY_EXISTS (20240827/dsfield-184)

As a side note how are you liking the w880? That was one was my second choice but wanted the 10G NIC.

Hmm interesting i don't have any of those errors. It was suggested in the general support forum that i add this to my startup
append initrd=/bzroot pcie_aspm=off
This appears to have gotten rid of those errors for the time being also had an issue with the samsung 990 pro nvme which i believe flashing to the latest firmware will fix it randomly disappearing.

Overall the board is working fine, just waiting for another set of 2x32gb ecc udimms to arrive. I only have 2gb internet coming in and still use a pcie 2.5gb nic in the very bottom slot. If i need 10gb which i probably won't ever need i can always swap them over.
Only thing i haven't got to work is the BMC- Tprobe location as i would like to monitor the temps of 1 hdd and adjust fancurve in my case.

8 hours ago, Solarisfps said:

Only thing i haven't got to work is the BMC- Tprobe location as i would like to monitor the temps of 1 hdd and adjust fancurve in my case.

Fan control is the next thing I need to work on. I was able to get the fan speeds to get reported finally.

19 hours ago, Solarisfps said:

Only thing i haven't got to work is the BMC- Tprobe location as i would like to monitor the temps of 1 hdd and adjust fancurve in my case.

Have you been able to get the IPMI working yet?

3 hours ago, kimocal said:

Have you been able to get the IPMI working yet?

Yes it has worked since day 1 no issues using remote screen with kvm functions fine. IPMI unraid plugin works and reports the information from the ipmi.

On 4/9/2025 at 2:51 AM, SimonF said:

you may need nct6687 plugin I need for msi z890

@SimonF I have the nct6687 installed and I have an Asus Z890 Pro board with an core ultra 7. I am not able to see any PWM controllers show up. Is there a setting a need to change?

Edited December 24, 2025Dec 24 by parish99

1 hour ago, parish99 said:

@SimonF I have the nct6687 installed and I have an Asus Z890 Pro board with an core ultra 7. I am not able to see any PWM controllers show up. Is there a setting a need to change?

I only get temps not been able to get fans showing. I needed to load nct6778 plug to get fans but does not show all. There is an option for MSI which I will need to try.

I was able to load modprobe nct6775 and I am now getting my pwm fan controllers!

Edited January 1Jan 1 by parish99

Hey

Enjoying this thread. I too try to understand c-states and how to optimize for low power.

I run Nixos (25.11) on:

• Intel Core Ultra 5 225

• Asus Strix B860-I (Itx)

• 32Gb of DDR5 5600Mhz ram

• Crucial P510 2TB

• Corsair RM650e

I too can only get acpi-idle stats for C1-3 in powertop/turbostat/cpupower. I measured the power draw with blank screen and heavy bios/OS power optimization. I seem to average 15.5W (between 13 and 17). I'm fine with that number but it feels irritating you pay €300 + €200 for a MB and CPU and it doesn't work as advertised.

May I ask what you mean by “advertised”?
Given the hardware you mentioned, I would expect power consumption of perhaps 6-8 watts for the parts. You’re now at 2 watts more. (Measured at the outlet at 15 watts, with perhaps 70% efficiency with your power supply)

And there might also be a 1–2-watt measurement margin of error. In this extremely low range, you really need professional measuring tools to get an accurate reading.

Intel seems to have listed specs for arrow lake finally:

1. You will never reach C10 without PSR or display off. AFAIK DP/eDP is required for PSR.

https://edc.intel.com/content/www/us/en/design/products/platforms/details/arrow-lake-s/core-ultra-200s-series-processors-datasheet-volume-1-of-2/package-c-states/

PKG C10

Display in PSR or powered, ff all VRs at PS4 or LPM + crystal clock off.

The processor will enter Package C10 when:

All IA cores in C10 + Processor Graphic cores in RC6.

The platform components/devices allow proper LTR for entering Package C10.

2. Single display, 60Hz max, and PSR on for C10:

https://edc.intel.com/content/www/us/en/design/products/platforms/details/arrow-lake-s/core-ultra-200s-series-processors-datasheet-volume-1-of-2/package-c-states-and-display-resolutions/

PSR off? Max C8 forever.

3. Powertop reporting only 3 states and intel saying it won't be fixed ever:

https://edc.intel.com/content/www/us/en/design/products/platforms/details/arrow-lake-s/core-ultra-200s-series-processors-datasheet-volume-1-of-2/processor-ia-core-c-state-rules/

C6-C10

MWAIT(C6/C8/10) or IO read=P_LVL3//6/8

4. Graphics tweaks

https://edc.intel.com/content/www/us/en/design/products/platforms/details/arrow-lake-s/core-ultra-200s-series-processors-datasheet-volume-1-of-2/memory-power-savings-technologies/

Memory Power Savings Technologies

Display Power Savings Technologies

Processor Graphics Core Power Savings Technologies

Intel lpmd does not exist for Arrow Lake: 🤣

https://github.com/intel/intel-lpmd/issues/97

Edited May 12May 12 by knotgerman

@knotgerman You seem pretty active in this discussion. Are you certain intel_idle is the issue? Per https://github.com/torvalds/linux/blob/master/drivers/idle/intel_idle.c, Arrow Lake isn't explicitly mentioned, but shouldn't it use the Meteor Lake data?

I'm running ASUS PRIME Z890M-PLUS WIFI (latest beta BIOS 3020) + Intel Core Ultra 5 245K (microcode 0x121) + Proxmox VE 9.1.11 (kernel 7.0.2-2-pve).

I compiled the latest powertop and I'm seeing zero package C-state residency despite all cores being in C6 or C7 85-100% of the time. pcm confirms the same. I can enter package C2 if I stop all services on my server, but nothing deeper. This also drops me to around 8-9 W vs. 11 W normally. Wonder if I'm just chasing non-existent gains.

I have all ASPM and C-state settings enabled and 'maxed out' in BIOS (besides native ASPM, so that ASPM is managed by BIOS) and confirmed with lspci, checked MSR register 0xE2, etc. Gone down multiple rabbit holes and I can't pinpoint any issues. Don't want to enable runtime PM for SATA controller + disks as suggested by powertop since I'm using ZFS. Doubtful it's causing any issues but I could very well be wrong.

Maybe my integrated RTL8125 / r8169 driver is at fault (even though lspci reports that ASPM is enabled)...? The PSR stuff doesn't seem relevant for a headless server. I do see Low Power S0 Idle (V5) : 0 in FADT as others have pointed out, but I'm not quite sure if S0 is relevant here either?

Edited May 15May 15 by encryptedcurse

Yes. powertop will never work so give up. You can read my previous posts. Cx_ACPI = C6/C8/C10. Read the intel docs--they aren't fixing it and the reporting will stay broken.

RTL8125 works fine with ASPM fully enabled.

Same chip and same MB as me. I can't get lower than 12W, so you beat me with 8-9W. Getting S0ix enabled is the "holy grail" to hit the same low power as Alder Lake/12th gen; however, you seem to be almost there... somehow.

# lspci -vv | awk '/ASPM/{print $0}' RS= | grep --color -P '(^[a-z0-9:.]+|ASPM )'

Can you post the above?

@knotgerman Right, I understand that the current stable release of powertop (2.15) reports ACPI C-states, but 2.16-rc3 should have Arrow Lake support so there shouldn't be any more reporting issues, in theory. pcm should report correctly as well.

Here's what I see with powertop 2.16-rc3...

        Package(HW) |
C2 (pc2)   57.7%    |
C3 (pc3)    0.0%    |
C6 (pc6)    0.0%    |
C7 (pc7)    0.0%    |
C8 (pc8)    0.0%    |
C9 (pc9)    0.0%    |
C10 (pc10)  0.0%    |

...and pcm 202502-1:

 Core C-state residencies: C0 (active,non-halted): 0.15 %; C1: 0.32 %; C3: 0.00 %; C6: 57.70 %; C7: 41.83 %;
 Package C-state residencies:  C0: 100.00 %; C2: 0.00 %; C4: 0.00 %; C6: 0.00 %;
                             ┌───────────────────────────────────────────────────────────────────────────────┐
 Core    C-state distribution│6666666666666666666666666666666666666666666666777777777777777777777777777777777│
                             └───────────────────────────────────────────────────────────────────────────────┘
                             ┌────────────────────────────────────────────────────────────────────────────────┐
 Package C-state distribution│00000000000000000000000000000000000000000000000000000000000000000000000000000000│
                             └────────────────────────────────────────────────────────────────────────────────┘

I'm not convinced I'm hitting past C0 (or C2, if we're being generous — not sure why powertop doesn't show pc0).

FYI, the 8-9 W I quoted is with practically nothing running. I get to 11-12 W regularly.

Are you using the Realtek-provided r8125 driver or the generic r8169?

Do you plan to edit the BIOS to enable S0ix? I looked into it very briefly, but I'm not sure I'm ready to take the risk yet.

lspci output as you requested:

root@pve:~# lspci -vv -k | awk '/ASPM/{print $0}' RS= | grep --color -P '(^[a-z0-9:.]+|ASPM |Kernel)'
pcilib: sysfs_read_vpd: read failed: No such device
00:01.0 PCI bridge: Intel Corporation Meteor Lake-H PCIe Root Port (rev 10) (prog-if 00 [Normal decode])
                LnkCap: Port #12, Speed 32GT/s, Width x4, ASPM L0s L1, Exit Latency L0s <4us, L1 <64us
                LnkCtl: ASPM L1 Enabled; RCB 64 bytes, LnkDisable- CommClk+
        Kernel driver in use: pcieport
        Kernel modules: shpchp
00:06.0 PCI bridge: Intel Corporation Arrow Lake-HX PCIe Root Port #13 (rev 10) (prog-if 00 [Normal decode])
                LnkCap: Port #13, Speed 32GT/s, Width x16, ASPM L0s L1, Exit Latency L0s unlimited, L1 <64us
                LnkCtl: ASPM L0s L1 Enabled; RCB 64 bytes, LnkDisable- CommClk-
        Kernel driver in use: pcieport
        Kernel modules: shpchp
01:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller S4LV008[Pascal] (prog-if 02 [NVM Express])
                LnkCap: Port #0, Speed 16GT/s, Width x4, ASPM L1, Exit Latency L1 <64us
                LnkCtl: ASPM L1 Enabled; RCB 64 bytes, LnkDisable- CommClk+
        Kernel driver in use: nvme
        Kernel modules: nvme
80:1b.0 PCI bridge: Intel Corporation 800 Series PCH PCIe Root Port #17 (rev 10) (prog-if 00 [Normal decode])
                LnkCap: Port #17, Speed 16GT/s, Width x1, ASPM L0s L1, Exit Latency L0s unlimited, L1 <64us
                LnkCtl: ASPM L0s L1 Enabled; RCB 64 bytes, LnkDisable- CommClk-
        Kernel driver in use: pcieport
        Kernel modules: shpchp
80:1c.0 PCI bridge: Intel Corporation 800 Series PCH PCIe Root Port #1 (rev 10) (prog-if 00 [Normal decode])
                LnkCap: Port #1, Speed 16GT/s, Width x1, ASPM L0s L1, Exit Latency L0s unlimited, L1 <64us
                LnkCtl: ASPM L0s L1 Enabled; RCB 64 bytes, LnkDisable- CommClk-
        Kernel driver in use: pcieport
        Kernel modules: shpchp
80:1c.2 PCI bridge: Intel Corporation Device 7f3a (rev 10) (prog-if 00 [Normal decode])
                LnkCap: Port #3, Speed 16GT/s, Width x1, ASPM L0s L1, Exit Latency L0s <4us, L1 <64us
                LnkCtl: ASPM L0s L1 Enabled; RCB 64 bytes, LnkDisable+ CommClk+
        Kernel driver in use: pcieport
        Kernel modules: shpchp
80:1c.3 PCI bridge: Intel Corporation Device 7f3b (rev 10) (prog-if 00 [Normal decode])
                LnkCap: Port #4, Speed 16GT/s, Width x1, ASPM L0s L1, Exit Latency L0s <4us, L1 <64us
                LnkCtl: ASPM L1 Enabled; RCB 64 bytes, LnkDisable- CommClk+
        Kernel driver in use: pcieport
        Kernel modules: shpchp
80:1d.0 PCI bridge: Intel Corporation 800 Series PCH PCIe Root Port #9 (rev 10) (prog-if 00 [Normal decode])
                LnkCap: Port #9, Speed 16GT/s, Width x4, ASPM L0s L1, Exit Latency L0s unlimited, L1 <64us
                LnkCtl: ASPM L0s L1 Enabled; RCB 64 bytes, LnkDisable- CommClk-
        Kernel driver in use: pcieport
        Kernel modules: shpchp
84:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller (rev 0c)
                LnkCap: Port #0, Speed 5GT/s, Width x1, ASPM L0s L1, Exit Latency L0s unlimited, L1 <64us
                LnkCtl: ASPM L1 Enabled; RCB 64 bytes, LnkDisable- CommClk+
        Kernel driver in use: r8169
        Kernel modules: r8169

Edited May 17May 17 by encryptedcurse

Powertop "arrow lake" patch does nothing. acpi_C1 = C6, C2 = C8, C3 = C10. That's it. I already posted about it being stuck in C2 with the "patch." C-states work; the reporting is just wrong.

pcm should work just like powertop should work. Intel doesn't care about arrow lake desktop. File a bug and see what Intel says. My guess is nothing.

r8169 kernel driver. You have ASPM fully enabled on the ethernet.

Your lspci looks identical to mine.

S0ix enablement should allow for deep power savings. I think the issue is pcie roots aren't turning off. I am not risking my mb editing EFI manually.

More:

https://z8.re/blog/aspm.html

https://krasovs.ky/2025/01/11/power-saving.html

Official intel s0ix: https://github.com/intel/S0ixSelftestTool

https://www.reddit.com/r/ASRock/comments/1998ozl/how_to_get_higher_pkg_cstates_on_asrock/

In the setup_script_file.txt current values is marked with asterisk “*”. Our goal is to change “Lower Power S0 Idle Capability” from 0x0 (Disabled) to 0x1 (Enabled).

From the command line you can check value/status by this command:

.\SCEWIN_64.exe /o /lang 'en-US' /ms "Low Power S0 Idle Capability" /hb

“*” next to “[00]Disabled” indicates it currently disabled. Then change it:

.\SCEWIN_64.exe /i /lang 'en-US' /ms "Low Power S0 Idle Capability" /qv 0x1 /cpwd YOUR-BIOS-ADMIN-PASSWORD /hb

Asrock can do it. Tried a few times but gave up.

22 hours ago, knotgerman said:

Powertop "arrow lake" patch does nothing. acpi_C1 = C6, C2 = C8, C3 = C10. That's it. I already posted about it being stuck in C2 with the "patch." C-states work; the reporting is just wrong.

pcm should work just like powertop should work. Intel doesn't care about arrow lake desktop. File a bug and see what Intel says. My guess is nothing.

r8169 kernel driver. You have ASPM fully enabled on the ethernet.

Your lspci looks identical to mine.

S0ix enablement should allow for deep power savings. I think the issue is pcie roots aren't turning off. I am not risking my mb editing EFI manually.

More:

https://z8.re/blog/aspm.html

https://krasovs.ky/2025/01/11/power-saving.html

Official intel s0ix: https://github.com/intel/S0ixSelftestTool

Asrock can do it. Tried a few times but gave up.

I see what you mean now. intel_idle.c is missing a arl_cstates[] struct and/or accompanying entry in the intel_idle_ids[] struct. 🙂

Really trivial to add...I've noticed Intel is very sloppy with their open source contributions.

Interestingly, they recently added the ability to specify your own C-states table.

However, I don't think we could just copy the Meteor Lake table 1:1 since the MWAIT instructions are different. 0x0 is trivial, but I don't know how you'd figure out the exit_latency and target_residency for the other two. Maybe something to look into if you're savvy, but I'm personally putting it on the backburner for now.

grep . /sys/devices/system/cpu/cpu0/cpuidle/state*/desc
/sys/devices/system/cpu/cpu0/cpuidle/state0/desc:CPUIDLE CORE POLL IDLE
/sys/devices/system/cpu/cpu0/cpuidle/state1/desc:ACPI FFH MWAIT 0x0
/sys/devices/system/cpu/cpu0/cpuidle/state2/desc:ACPI FFH MWAIT 0x21
/sys/devices/system/cpu/cpu0/cpuidle/state3/desc:ACPI FFH MWAIT 0x60

Edited May 19May 19 by encryptedcurse

@knotgerman Since it sounds like you went through the process of tinkering with SCEHUB/SCEWIN, did you manage to get nvram.txt? If so, could you share it?

Poked around the BIOS with UEFI Editor and found these somewhat interesting settings:

• Disable Turbo GT frequency

• CFG Lock

• Enable Configurable TDP

• Power Limit 3 /4

• Package Power Limit MSR Lock

• Energy Efficient P-state

• Low Power S0 Idle Capability

• DLRM Setting for Storage

Edited May 19May 19 by encryptedcurse

15 hours ago, encryptedcurse said:

Low Power S0 Idle Capability

Enable and test. That should be all that is needed. If you can find a "Multi-VC" toggle, try enabling that as well.

"Energy Efficient P-state" - unknown what that is but may be for newer LPe cores on say Panther Lake laptop chips.

DLMR was added to bios a while back.

Tried every single SCEHUB/SCEWIN binary out there including the latest MSI ones. Got close a few times but none worked.

Edited May 19May 19 by knotgerman