sys clk

Switch sysmodule allowing you to set cpu/gpu/mem clocks according to the running application and docked state.

Installation

The following instructions assumes you have a Nintendo Switch running Atmosphère, updated to at least the latest stable version.
Copy the config and atmosphere folder at the root of your sdcard, overwriting files if prompted.

Relevant files

• Config file allows one to set custom clocks per docked state and title id, described below

  /config/sys-clk/config.ini

• Log file where the log are written if enabled

  /config/sys-clk/log.txt

• Log flag file enables log writing if file exists

  /config/sys-clk/log.flag

Config

Presets can be customized by adding them to the ini config file located at /config/sys-clk/config.ini, using the following template for each app

[Application Title ID]
docked_cpu=
docked_gpu=
docked_mem=
handheld_charging_cpu=
handheld_charging_gpu=
handheld_charging_mem=
handheld_charging_usb_cpu=
handheld_charging_usb_gpu=
handheld_charging_usb_mem=
handheld_charging_official_cpu=
handheld_charging_official_gpu=
handheld_charging_official_mem=
handheld_cpu=
handheld_gpu=
handheld_mem=

• Replace Application Title ID with the title id of the game/application you’re interested in customizing.
  A list of games title id can be found in [Switchbrew wiki](https //switchbrew.org/wiki/Title_list/Games).
• Frequencies are expressed in mhz, and will be scaled to the nearest possible values, described in the clock table below.
• If any key is omitted, value is empty or set to 0, it will be ignored, and stock clocks will apply.
• If charging, sys clk will look for the frequencies in that order, picking the first found
  Charger specific config (USB or Official) handheld_charging_usb_X or handheld_charging_official_X
  Non specific charging config handheld_charging_X
  Handheld config handheld_X

Example 1 Zelda BOTW

• Overclock CPU when docked or charging
• Overclock MEM to docked clocks when handheld

Leads to a smoother framerate overall (ex in the korok forest)

[01007EF00011E000]
docked_cpu=1224
handheld_charging_cpu=1224
handheld_mem=1600

Example 2 Picross

• Underclocks on handheld to save battery

[0100BA0003EEA000]
handheld_cpu=816
handheld_gpu=153
handheld_mem=800

Capping

To protect the battery from excessive strain, clocks requested from config may be capped before applying, depending on your current profile:

Clock table (MHz)

MEM clocks

• 1600 > official docked, max clock
• 1331 > official handheld
• 1065
• 800
• 665

CPU clocks

• 1785 → max clock, will cause instability in certain configurations
• 1683
• 1581
• 1428
• 1326
• 1224 → sdev oc
• 1122
• 1020 → official docked & handheld
• 918
• 816
• 714
• 612

GPU clocks

• 921 → max clock
• 844
• 768 → official docked
• 691
• 614
• 537
• 460 → max handheld
• 384 → official handheld
• 307 → official handheld
• 230
• 153
• 76

Notes:

1. GPU overclock is capped at 460Mhz in handheld and capped at 768Mhz if charging, unless you’re using the official charger.
2. Clocks higher than 768MHz need the official charger is plugged in.