Main

The Main tab allows you to view and quickly change your most important CPU settings. The max and min sliders control the maximum and minimum CPU speed that your device will reach. Tap or slide the sliders to change the max and min settings.

On the bottom right, you can set the CPU governor. The governor controls your phone's behavior when choosing speeds between the max and min. The available governors vary from device to device and kernel to kernel. The interactive and ondemand governors, for example, will scale your CPU up to the max setting when the CPU usage is high, and bring it back down when it's lower. For a full list of common governors, see the section on the Governor tab below.

The text at the very top of the menu shows the current CPU settings. This may not always match the sliders or the CPU governor selector. The large CPU frequency display will change based on your selected governor and CPU load.

The Set on Boot checkbox allows SetCPU to set the Main tab settings when your device first boots, so you won't have to go back into SetCPU every time you reboot. The Set on Boot checkbox also starts the profiles service if profiles are enabled.

Accessing the menu here will bring up a few options. If you're going to be overclocking or changing voltage settings, it's recommended that you read the Safe Mode instructions. The Perflock Disabler option helps SetCPU work on certain HTC stock kernels. Finally, you can also return to the introduction screen of SetCPU here.

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Profiles

The Profiles tab, which is located to the right of the Main tab, allows you to customize the CPU settings based on events that happen to your device. For example, a very popular profile is to set the max CPU speed lower when the battery is under 50% capacity to save battery. To get started with profiles, check the Enable checkbox at the bottom and press the Add button at the top right of the Profiles tab. This launches the Edit Profile menu.

The Profiles tab lists the current saved profiles on your device. To enable and disable profiles, use the checkbox on the left. The Notifications checkbox gives you notifications in the Android status bar of which profile is currently active.

Each profile has a certain condition. This is what triggers the profile; that is, what must happen for SetCPU to set the profile. Conditions allow you to set up battery level, charging, screen off, in–call, and time profiles. You can change the condition at the top of the Edit Profile menu.

Each profile also has a priority option. Priority is how SetCPU decides between two or more profiles when multiple conditions are met. For example, if you have two profiles, one with a charging condition and one with a screen off condition, and your phone's screen is off and charging at the same time, the profile with the higher priority will be set. For priorities, exact numbers don't matter – just make sure the order is right. To see some examples of how priorities should be used, see the Example Profiles section below.

If no conditions are met, no profiles are active. SetCPU will revert to your last saved settings in the Main tab. This is also known as the Main profile if notifications are turned on.

Charging Condition

Setting a charging condition means this profile will only trigger when the device is charging. There are three charging conditions which may or may not apply to your device – Charging All, Charging AC, and Charging USB. Charging All is called whenever the device is plugged in, whether to a wall socket or a USB port. Charging AC is only called when the device is plugged into a wall socket, and Charging USB is only called when the device is plugged into a USB port. Some tablets will only charge using a wall socket, so keep this in mind.

Screen Off Condition

This profile will be active when the device's screen is turned off, and will be inactive when the device's screen is turned back on. Use it to limit the CPU speed when you're not using the device to save battery.

Battery Condition

This profile will trigger when the battery level is under a certain point. A slider will pop up with a battery percentage on it. Set the battery level to the level you want it to be.

Temperature Condition

This profile will trigger when your device's internal temperature sensor goes above a certain point. Set your desired temperature using the slider.

Time Condition

The time condition allows you to set certain CPU settings for a time of day. For example, this profile will only be active for the hour between 12:00 PM and 1:00 PM if the time span is set to 12:00 PM – 1:00 PM (ie. 12:00 – 13:00).

In-call Condition

This condition will trigger whenever you are in a call.

The Profiles tab also has menu options for backing up, restoring, and sharing profile settings. If you choose to back up your profiles, they will be saved with an automatic name on your internal storage. The Restore menu also looks on the root directory of your internal storage.

Governor

The Governor tab is an advanced menu that allows you to make changes to the behavior of certain goverors. If the currently selected governor is compatible with this menu, you'll see a list of tweakable options here. Check the Set on Boot box here to set these changes on boot, and the Set with Profiles box to set these changes, which are ordinarily reset, when the profile is switched. Some governors, like performance and powersave, do not have any options that can be changed with the Governor tab. If this happens, the tab will be disabled.

Here is a list of common governors. Many custom kernels have customized governors written by the community. For explanations of these, please contact the kernel's distributor.

• ondemand: Available in most kernels, and the default governor in many kernels. When the CPU load reaches a certain point (the up threshold), ondemand will rapidly scale the CPU up to meet demand, then gradually scale the CPU down when it isn't needed.
• interactive: Available in many kernels, and becoming the default scaling option in most official Android kernels. The interactive governor is functionally similar to the ondemand governor with an even greater focus on responsiveness.
• conservative: Available in some kernels. It is similar to the ondemand governor, but will scale the CPU up more gradually to better fit demand. Conservative provides a less responsive experience than ondemand, but can save battery.
• performance: Available in most kernels. It will keep the CPU running at the max set value at all times. This is very slightly more efficient than simply setting max and min to the same value and using ondemand.
• powersave: Available in some kernels. It will keep the CPU running at the min set value at all times.
• hotplug: Available with some multi–core systems. Similar to ondemand, but turns additional cores off when they're not being used.
• userspace: Used with a method for controlling the CPU speed that isn't used by SetCPU. Do not select the userspace governor.
• smartass: Included in some custom kernels. The smartass governor effectively gives the phone an automatic Screen Off profile, keeping speeds at a minimum when the phone is idle.

Voltages

The Voltages tab is only available with some custom kernels and devices. If the Voltages tab is available, it will automatically show up between the Governor and Profiles tabs. Otherwise, the Voltages tab is unavailable. The Voltages tab is an advanced feature that allows you to customize the voltage of each available CPU frequency of your device (usually called undervolting). The voltages that your phone ships with are usually slightly higher than needed. Since power consumption decreases quadratically with voltage, even slightly lower voltages can mean drastically lower power consumption, but that sometimes comes at the cost of device stability. The limits for stability vary from chip to chip, even across the same device, so your results with this menu will vary.

The Voltages tab will show a list of all the available CPU frequencies on your device and a corresponding voltage for all of them. To change the voltage at a certain frequency, tap the frequency's entry in the list, and use either the text box or slider to change the voltage. Click on the Apply button on the top right to save the voltages and try the new voltage out. When trying out new voltages, go down a very little amount at a time and apply the voltages. Stress test your device at the new frequency and voltage for some time before moving on to a lower voltage. If your device crashes, the voltage is probably not stable. Reboot your device and try again. Don't check the Set on Boot box before you're sure that the voltage set you've saved is stable!

The Voltage tab has the potential to be dangerous, since higher voltages mean that the CPU will produce more heat. You almost never want to raise the voltage above the default at any frequency. Most of the time, unstable voltages will just crash the device, but use it with caution!

If you access the menu in this tab, you can choose to back up, restore, and share voltage settings, like you can with profiles. They will be saved to the internal storage or SD card. There is also an option to restore all the voltages to the kernel's default. Reboot your phone to complete this operation.

Info

The Info tab allows you to view information about your kernel, CPU, battery, phone, and memory status. It also includes a few benchmarks for testing the speed of the phone.

You can find the benchmark options in the menu at the bottom. The lower the benchmark score, the faster the phone is running. Keep in mind that the score from the short and long benchmarks can only be used to accurately compare different frequencies across the same ROM and kernel. The score may fluctuate between runs due to interference by background processes. For the best results, use the performance governor or set the max and min to be the same. There is also a stress test function. Stress testing allows you to test the stability of voltage settings or higher overclocks. The stress test will stress your CPU, pushing it to its thermal limits. The phone may be somewhat unresponsive during this time. The stress test will continue forever, so you have to manually end it after some time. To do this, simply press the back button on the phone. The stress test may end by itself if your phone is especially unstable, however.

To copy the current system info menu to the clipboard, press the copy button on the top right. There's also a share button.