[SOLVED] During sustained load, the 7840U's package power draw drops to 15W and stays there

Look at the first reply for answer.
Which Linux distro are you using?
Archlinux 6.15.5-arch1
Bios 3.9

So I was compiling the linux kernel and I noticed a sudden slow down of the time it took to compile each module. I fired up s-tui and I saw that the thermals were ok (below 70 celsius) but the packge power draw was 15W.

At first I assume that this was some kind of throttle but after a while and with the laptop completely cold I firre up the s-tui stress mode, and package power consumption was still 15W. A reboot was needed to fix the situation.

After a while and while already stuck at 15W power draw I could see “Sensor2,0” which I believe corresponds to the nvme pcie

nvme-pci-0200
Adapter: PCI adapter
Composite:
  temp1_input: 57.850
  temp1_max: 81.850
  temp1_min: -273.150
  temp1_crit: 84.850
  temp1_alarm: 0.000
Sensor 1:
  temp2_input: 57.850
  temp2_max: 65261.850
  temp2_min: -273.150
Sensor 2:
  temp3_input: 85.850
  temp3_max: 65261.850
  temp3_min: -273.150

Some info I gathered while compiling the linux kernel:

ryzenadj -i
detected compatible ryzen_smu kernel module
CPU Family: Phoenix Point
SMU BIOS Interface Version: 15
Version: v0.17.0
PM Table Version: 4c0009
|        Name         |   Value   |     Parameter      |
|---------------------|-----------|--------------------|
| STAPM LIMIT         |    47.282 | stapm-limit        |
| STAPM VALUE         |    15.005 |                    |
| PPT LIMIT FAST      |    53.000 | fast-limit         |
| PPT VALUE FAST      |    16.497 |                    |
| PPT LIMIT SLOW      |    15.000 | slow-limit         |
| PPT VALUE SLOW      |    15.003 |                    |
| StapmTimeConst      |     0.000 | stapm-time         |
| SlowPPTTimeConst    |     0.000 | slow-time          |
| PPT LIMIT APU       |    41.000 | apu-slow-limit     |
| PPT VALUE APU       |     0.000 |                    |
| TDC LIMIT VDD       |    54.000 | vrm-current        |
| TDC VALUE VDD       |    10.908 |                    |
| TDC LIMIT SOC       |    16.000 | vrmsoc-current     |
| TDC VALUE SOC       |     3.463 |                    |
| EDC LIMIT VDD       |   105.000 | vrmmax-current     |
| EDC VALUE VDD       |    17.967 |                    |
| EDC LIMIT SOC       |    23.000 | vrmsocmax-current  |
| EDC VALUE SOC       |     4.849 |                    |
| THM LIMIT CORE      |   100.000 | tctl-temp          |
| THM VALUE CORE      |    62.616 |                    |
| STT LIMIT APU       |    43.500 | apu-skin-temp      |
| STT VALUE APU       |    43.591 |                    |
| STT LIMIT dGPU      |     0.000 | dgpu-skin-temp     |
| STT VALUE dGPU      |     0.000 |                    |
| CCLK Boost SETPOINT |       nan | power-saving /     |
| CCLK BUSY VALUE     |       nan | max-performance    |
turbostat
turbostat version 2025.04.06 - Len Brown <lenb@kernel.org>
Kernel command line: initrd=\initramfs-linux.img rd.luks.name=dac92b71-e60e-419a-9e57-68e3a7202d8a=luksdev root=/dev/mapper/luksdev rw mitigations=off
CPUID(0): AuthenticAMD 0x10 CPUID levels
CPUID(1): family:model:stepping 0x19:74:1 (25:116:1) microcode 0x0
CPUID(0x80000000): max_extended_levels: 0x80000028
CPUID(1): SSE3 MONITOR - - - TSC MSR - HT -
CPUID(6): APERF, No-TURBO, No-DTS, No-PTM, No-HWP, No-HWPnotify, No-HWPwindow, No-HWPepp, No-HWPpkg, No-EPB
CPUID(7): No-SGX No-Hybrid
cpu0: cpufreq driver: amd-pstate-epp
cpu0: cpufreq governor: performance
cpufreq boost: 1
/dev/cpu_dma_latency: 2000000000 usec (default)
current_driver: acpi_idle
current_governor: menu
current_governor_ro: menu
cpu0: POLL: CPUIDLE CORE POLL IDLE
cpu0: C1: ACPI FFH MWAIT 0x0
cpu0: C2: ACPI IOPORT 0x414
cpu0: C3: ACPI IOPORT 0x415
RAPL: 234 sec. Joule Counter Range, at 280 Watts
cpu0: MSR_RAPL_PWR_UNIT: 0x000a1003 (0.125000 Watts, 0.000015 Joules, 0.000977 sec.)
Core    CPU     Avg_MHz Busy%   Bzy_MHz TSC_MHz IPC     IRQ     NMI     SMI     POLL%   C1%     C2%     C3%     CorWatt PkgWatt
-       -       1440    99.97   1441    3294    1.17    90423   4       0       0.00    0.00    0.02    0.00    9.43    14.87
0       0       1440    99.98   1441    3294    1.27    5423    0       0       0.00    0.00    0.02    0.00    1.16    14.87
0       1       1440    99.98   1441    3294    1.20    6143    0       0       0.00    0.00    0.02    0.00
1       2       1440    99.90   1441    3294    1.25    5772    0       0       0.00    0.00    0.05    0.05    1.22
1       3       1440    99.92   1441    3294    1.19    5596    0       0       0.00    0.00    0.08    0.00
2       4       1441    100.00  1441    3294    1.16    5493    0       0       0.00    0.00    0.00    0.00    1.19
2       5       1441    100.00  1441    3294    1.16    5263    1       0       0.00    0.00    0.00    0.00
3       6       1440    99.94   1441    3294    1.16    5538    0       0       0.00    0.00    0.06    0.00    1.18
3       7       1440    99.96   1441    3294    1.13    5645    0       0       0.00    0.00    0.04    0.00
4       8       1441    99.99   1441    3294    1.23    5361    0       0       0.00    0.00    0.01    0.00    1.15
4       9       1440    99.98   1441    3294    1.11    6157    0       0       0.00    0.00    0.01    0.00
5       10      1441    100.00  1441    3294    1.16    5709    1       0       0.00    0.00    0.00    0.00    1.20
5       11      1441    99.99   1441    3294    1.18    5451    0       0       0.00    0.00    0.01    0.00
6       12      1440    99.99   1441    3294    1.13    5791    1       0       0.00    0.00    0.01    0.00    1.20
6       13      1441    100.00  1441    3294    1.12    5757    1       0       0.00    0.00    0.00    0.00
7       14      1440    99.94   1441    3294    1.19    5963    0       0       0.00    0.00    0.05    0.00    1.13
7       15      1441    100.00  1441    3294    1.16    5361    0       0       0.00    0.00    0.00    0.00
Core    CPU     Avg_MHz Busy%   Bzy_MHz TSC_MHz IPC     IRQ     NMI     SMI     POLL%   C1%     C2%     C3%     CorWatt PkgWatt
-       -       1449    99.95   1450    3293    1.17    91267   3       0       0.00    0.00    0.05    0.01    9.47    14.86
0       0       1449    99.99   1450    3294    1.17    5357    0       0       0.00    0.00    0.01    0.00    1.17    14.87
0       1       1448    99.90   1450    3294    1.06    6294    0       0       0.00    0.00    0.10    0.00
1       2       1450    100.00  1450    3294    1.21    5445    0       0       0.00    0.00    0.00    0.00    1.21
1       3       1448    99.86   1450    3294    1.26    5689    1       0       0.00    0.00    0.10    0.04
2       4       1450    100.00  1450    3294    1.17    5646    1       0       0.00    0.00    0.00    0.00    1.20
2       5       1450    100.00  1450    3294    1.13    5390    0       0       0.00    0.00    0.00    0.00
3       6       1449    99.95   1450    3294    1.24    5855    0       0       0.00    0.00    0.05    0.00    1.20
3       7       1450    99.99   1450    3294    1.18    5379    0       0       0.00    0.00    0.00    0.00
4       8       1449    99.99   1450    3294    1.18    5383    0       0       0.00    0.00    0.01    0.00    1.19
4       9       1448    99.87   1450    3294    1.15    6223    0       0       0.00    0.00    0.10    0.01
5       10      1450    100.00  1450    3294    1.17    5419    0       0       0.00    0.00    0.00    0.00    1.17
5       11      1450    99.99   1450    3294    1.15    5528    0       0       0.00    0.00    0.01    0.00
6       12      1449    99.92   1450    3294    1.15    5988    0       0       0.00    0.00    0.08    0.00    1.18
6       13      1449    99.94   1450    3294    1.09    5919    0       0       0.00    0.00    0.05    0.00
7       14      1446    99.77   1450    3294    1.16    5967    1       0       0.00    0.00    0.19    0.04    1.15

Is the pcie nvme temperature sensor triggering a the throttle?

Your problem is very similar to this one.

1 Like

Oh right, thanks!