It allows you to:

- read current fan speeds and modes

- switch modes of each of the three available fans

- control fan speed in `fixed` mode

- control fan speed with custom curves in `curve` mode

- read current power mode

- change current power mode

- read current APU temperature

5. Run `scripts/info.sh` and check that all information is there.

6. Run `scripts/test_fan_mode_fixed.sh`, it should test your fans on all 6 fixed levels.

Reading and writing all of the parameters happens through sysfs with `/sys/class/ec_su_axb35` path. You can find detailed information in [the repo's readme file](https://github.com/cmetz/ec-su_axb35-linux/blob/main/README.md).

Some examples:

- `cat /sys/class/ec_su_axb35/fan2/rpm` to get current rpm of fan2

- `echo fixed > /sys/class/ec_su_axb35/fan3/mode && echo 2 > /sys/class/ec_su_axb35/fan3/level` to switch fan3 to fixed mode and set speed to level 2

- `echo balanced > /sys/class/ec_su_axb35/apu/power_mode` to set power mode to balanced (85W)

To apply specific settings at system startup, place them in your `rc.local` file or utilize any other methods for executing commands during boot, such as creating a systemd unit. In the future, these parameters will also be configurable through module options.

The custom curves define temperature thresholds for fan power levels:

- **Ramp-up curve** (`/sys/class/ec_su_axb35/fanX/rampup_curve`): temperature points where fan increases to the next level

For example, with these settings:

- Below 60°: Fan at level 0 (minimum)

- At 60°: Increases to level 1

- At 70°: Increases to level 2

- At 83°: Increases to level 3

- At 95°: Increases to level 4

- At 97°: Increases to level 5 (maximum)

- Above 96°: Fan stays at level 5

- Below 96°: Decreases to level 4

- Below 94°: Decreases to level 3

- Below 80°: Decreases to level 2

- Below 50°: Decreases to level 1

- Below 40°: Decreases to level 0

This creates a buffer at each level that prevents the fan from rapidly switching between speeds when temperature fluctuates around threshold values.

Curves are being applied only when `curve` mode is set on a specific fan, each fan has their own curves.

Main 3 parameters we are interested in are:

- `STAPM LIMIT` (sustained power draw)

- `PPT LIMIT FAST` (boost power draw)

- `PPT LIMIT SLOW` (average power draw)

Default values on all 3 selectable power modes (use `ryzenadj --info` to read them):

| Power Mode | STAPM LIMIT | PPT LIMIT FAST | PPT LIMIT SLOW |

| ----------- | ----------- | -------------- | -------------- |

| Quiet | 54.0 | 100.0 | 54.0 |

| Balanced | 85.0 | 120.0 | 120.0 |

| Performance | 120.0 | 140.0 | 120.0 |

Example on setting the power limit to static 100W with no boost:

- [[Guides/Power-Modes-and-Performance]]