How to slow down iMac CPU for quiet operation [duplicate]
When there is less than 5% battery left on a mac, the battery indicator goes red and system performance significantly drops - presumably in an attempt to make that remaining 5% last a little longer.
Is there a way to manually trigger this, so that the system performance is low (and battery life longer), even when there is plentiful battery?
This would theoretically be a way of extending the number of hours on a battery beyond the rated amount.
I'm using underclocking app volta, seems to be working so far.
Energy Saver preferences
The easiest way to manage your power consumption on a MacBook model is to use the Energy Saver preference Pane.
- Go to Apple > System Preferences
- Select the Energy Saver preference pane
- You'll now have access to a range of settings.
- Since you're interested in reducing power usage while on battery power, select the Battery tab.
NOTE: The options you'll have here will depend on your Mac model and version of macOS. For example, models with both built-in and dedicated graphics cards will provide a graphics switching checkbox that configures your Mac to automatically switch between graphics modes to improve battery life.
Display brightness
The most obvious other factor that can reduce battery consumption is reducing the brightness level of your built-in display. You can access this from Apple > System Preferences > Displays.
Further reading
You may find the following resources useful:
- Use the Energy Saver settings on your Mac
- About Energy Saver sleep and idle modes in Mac OS X
Just adding to Monomeeth's answer:
- Quitting all applications not currently needed or in active use
- disabling Bluetooth and WiFi, if possible
- disabling as much options, services, background processes etc. as possible (anything related to syncing, overcrowded Notification Center…)
Lowering the Processor Speed:
- and closest to what you directly asked: disable at least TurboBoost on the main processor with e.g. Turbo Boost Switcher. That will keep your CPU cooler, less Watt-hungry and, if you have fans, keeps your fans down.