What does Power Mode do exactly?

[Leokuma]

Hi all 👋.

I noticed that if I set Power Mode to Performance, my CPU usage goes down and its temperature goes up, whereas in Power Saver my CPU usage goes up and its temperature goes down.

Can anyone explain what's going on here? I expected Power Saver Mode to use less CPU than Performance Mode. I also expected a CPU with more workload to generate more heat than the same CPU with less workload.

Maybe Intel sensors are misleading? The indicated temperatures don't seem to be consistent between Linux and Windows, running on the same machine.

My CPU doesn't have integrated graphics. My graphics card is an Nvidia GeForce GTX 1050.

This is a video demonstrating the described behavior:

2025-03-09.14-59-30.mp4

inxi -F

~ ❯ inxi -F                                                                                                                                  15:13:09
System:
  Host: leo-pc Kernel: 6.8.0-55-generic arch: x86_64 bits: 64
  Desktop: Cinnamon v: 6.4.8 Distro: Linux Mint 22.1 Xia
Machine:
  Type: Desktop System: ASUS product: N/A v: N/A serial: <superuser required>
  Mobo: ASUSTeK model: PRIME B760-PLUS D4 v: Rev 1.xx
    serial: <superuser required> UEFI: American Megatrends v: 0402
    date: 10/14/2022
CPU:
  Info: quad core model: 12th Gen Intel Core i3-12100F bits: 64 type: MT MCP
    cache: L2: 5 MiB
  Speed (MHz): avg: 800 min/max: 800/4300 cores: 1: 800 2: 800 3: 800 4: 800
    5: 800 6: 800 7: 800 8: 800
Graphics:
  Device-1: NVIDIA GP107 [GeForce GTX 1050] driver: nvidia v: 550.120
  Display: x11 server: X.Org v: 21.1.11 with: Xwayland v: 23.2.6 driver: X:
    loaded: nouveau unloaded: fbdev,modesetting,vesa failed: nvidia
    gpu: nvidia,nvidia-nvswitch resolution: 3840x2160~60Hz
  API: EGL v: 1.5 drivers: nvidia,swrast platforms: x11,surfaceless,device
  API: OpenGL v: 4.6.0 compat-v: 4.5 vendor: nvidia mesa v: 550.120
    renderer: NVIDIA GeForce GTX 1050/PCIe/SSE2
Audio:
  Device-1: Intel Raptor Lake High Definition Audio driver: snd_hda_intel
  Device-2: NVIDIA GP107GL High Definition Audio driver: snd_hda_intel
  API: ALSA v: k6.8.0-55-generic status: kernel-api
  Server-1: PipeWire v: 1.0.5 status: active
Network:
  Device-1: Realtek RTL8125 2.5GbE driver: r8169
  IF: eno1 state: up speed: 1000 Mbps duplex: full mac: <censored>
RAID:
  Hardware-1: Intel Volume Management Device NVMe RAID Controller driver: vmd
Drives:
  Local Storage: total: 1.37 TiB used: 722.83 GiB (51.6%)
  ID-1: /dev/nvme0n1 vendor: Samsung model: SSD 980 PRO 500GB
    size: 465.76 GiB
  ID-2: /dev/nvme1n1 vendor: Samsung model: SSD 990 PRO with Heatsink 1TB
    size: 931.51 GiB
  ID-3: /dev/sda vendor: Generic model: STORAGE size: 3.69 GiB type: USB
Partition:
  ID-1: / size: 180.89 GiB used: 123.72 GiB (68.4%) fs: ext4
    dev: /dev/nvme1n1p4
  ID-2: /boot/efi size: 512 MiB used: 6.1 MiB (1.2%) fs: vfat
    dev: /dev/nvme1n1p3
Swap:
  ID-1: swap-1 type: file size: 2 GiB used: 0 KiB (0.0%) file: /swapfile
Sensors:
  System Temperatures: cpu: 38.8 C mobo: N/A gpu: nvidia temp: 39 C
  Fan Speeds (rpm): N/A gpu: nvidia fan: 50%
Info:
  Memory: total: 16 GiB available: 15.43 GiB used: 2.84 GiB (18.4%)
  Processes: 324 Uptime: 2h 54m Shell: Zsh inxi: 3.3.34

[rcalixte]

I noticed that if I set Power Mode to Performance, my CPU usage goes down and its temperature goes up, whereas in Power Saver my CPU usage goes up and its temperature goes down.

Can anyone explain what's going on here? I expected Power Saver Mode to use less CPU than Performance Mode. I also expected a CPU with more workload to generate more heat than the same CPU with less workload.

Think of it like a car engine. When you put it in Performance mode, it uses more gas (temperature goes up along with power consumption) but it's also easier to go faster (CPU goes down). When you put it in Power Saver mode, it uses less gas (temperature and power consumption go down) but it needs more work to go as fast.

You should also keep in mind that not all CPU workloads are equivalent. It is a complex topic but your web browser, file manager, image viewer, code editor, code compiler, and calculator all use CPU very differently. It is a resource just like storage or memory.

All this to say, your observations are normal and expected.