Raspberry Pi Configuration Tool (raspi-config)

Please share with your friends...
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  

8. Overclock

The Raspberry Pi supports simple software-based overclocking. The following table shows the stock speeds for each model:

Model ARM CPU Core SDRAM
Raspberry Pi 700 MHz 250 MHz 400 MHz
Raspberry Pi 2 900 MHz 250 MHz 450 MHz
Raspberry Pi Zero 1000 MHz

Most of the first generation could be overclocked to 800 MHz and some even higher to 1000 MHz. There are reports that the second generation can be overclocked similarly.

However, results will vary, and overclocking too high may result in instability and reduce the lifetime of your Raspberry Pi.

Be aware that overclocking may reduce the lifetime of your Raspberry Pi. If overclocking at a certain level causes system instability, try a more modest overclock. Hold down shift during boot to temporarily disable overclock.
See http://elinux.org/RPi_Overclocking for more information.

Using an overclocking preset through raspi-config does not void your warranty. Other methods, such as manually setting an overvolt value in /boot/config.txt, sets a permanent sticky bit within the SoC – making it possible to detect that the Pi has been overclocked beyond specifications.

There are five overclock presets for the Raspberry Pi, and one specifically for the Raspberry Pi 2. Note that raspi-config currently does not have a None preset to support the Pi2 – to revert from an overclock preset with the Pi2, you will need to edit the /boot/config.txt file directly.

Preset ARM CPU Core SDRAM Overvolts
None 700 MHz 250 MHz 400 MHz 0 Volts
Modest 800 MHz 250 MHz 400 MHz 0 Volts
Medium 900 MHz 250 MHz 450 MHz 2 Volts
High 950 MHz 250 MHz 450 MHz 6 Volts
Turbo 1000 MHz 500 MHz 600 MHz 6 Volts
Pi2 1000 MHz 500 MHz 500 MHz 2 Volts

The Turbo and Pi2 presets enable dynamic overclocking and overvoltage control, applying turbo when busy and limiting turbo when the SoC temperature reaches 85°C – meaning there should be no measurable reduction in the lifetime of your Raspberry Pi.

Overclock is disabled by default.

  1. Start at the raspi-config main menu.
    Overclock

    Overclock

  2. Select Overclock. A message warning about the risks of overclocking will be displayed.
    Overclock warning

    Overclock warning

  3. Select Ok. A message asking Choose overclock preset will be displayed.
    Choose overclock preset

    Choose overclock preset

  4. Select the desired overclock preset and press Enter.

Enabling an Overclock option makes the following changes to /boot/config.txt

None

Standard clock settings for Raspberry Pi. Not intended for Raspberry Pi 2.

arm_freq=700
core_freq=250
sdram_freq=400
over_voltage=0
Modest

Modest overclock settings for Raspberry Pi. Not intended for Raspberry Pi 2.

arm_freq=800
core_freq=250
sdram_freq=400
over_voltage=0
Medium

Medium overclock settings for Raspberry Pi. Not intended for Raspberry Pi 2.

arm_freq=900
core_freq=250
sdram_freq=450
over_voltage=2
High

High overclock settings for Raspberry Pi. Not intended for Raspberry Pi 2.

arm_freq=950
core_freq=250
sdram_freq=450
over_voltage=6
Turbo

Turbo overclock settings for Raspberry Pi provides a turbo clock speed of 1 GHz! Not intended for Raspberry Pi 2.

arm_freq=1000
core_freq=500
sdram_freq=600
over_voltage=6
Pi2

Pi2 overclock settings for Raspberry Pi 2 provides a turbo clock speed of 1 GHz! Not intended for original model Raspberry Pi.

arm_freq=1000
core_freq=500
sdram_freq=500
over_voltage=2

To disable, you must manually remove these lines from the /boot/config.txt file

The following are additional overclocks for the Raspberry Pi 2 that must be manually added to /boot/config.txt

Pi2 Cool

Pi2 Cool clock settings for Raspberry Pi 2 helps lower board temperatures as the ARM, SDRAM and CORE clocks will only run at normal speed when needed. Not intended for original model Raspberry Pi.

arm_freq_min=400
sdram_freq_min=250
core_freq_min=250
initial_turbo = 30 # Does not affect warranty. (Speeds up boot)
Pi2 GPU MEM

Pi2 GPU MEM overclock settings for Raspberry Pi 2 improves performance without overlocking the ARM processor (arm_freq), which can add a lot of heat to the board when pushed. Not intended for original model Raspberry Pi.

core_freq=500
sdram_freq=500
over_voltage=2
Pi2 Extreme

Pi2 Extreme overclock settings for Raspberry Pi 2 provides a turbo clock speed of 1.1 GHz! Not intended for original model Raspberry Pi.

arm_freq=1100
core_freq=500
sdram_freq=500
over_voltage=6
temp_limit=80 # Will throttle to default clock speed if hit.
Pi2 Void Warranty

Pi2 Void Warranty overclock settings for Raspberry Pi 2 provides a fixed clock speed of 1.1 GHz! This method does not use dynamic frequency control, and hence overcomes the inherit performance lag, but will void your warranty as it disables thermal protection and throttling in the ARM processor. Not intended for original model Raspberry Pi.

force_turbo=1 #Voids Warranty!!!
arm_freq=1100
sdram_freq=500
core_freq=500
over_voltage=6
temp_limit=80 # Will throttle to default clock speed if hit.

The following table lists the Raspberry Pi overclocking entries available for /boot/config.txt

arm_freq Frequency of ARM in MHz
arm_freq_min Minimum value of arm_freq used for dynamic clocking.
boot_delay Wait for x number of seconds in start.elf before loading kernel. Default 1
core_freq Frequency of GPU processor core in MHz. It has an impact on ARM performance since it drives L2 cache.
core_freq_min Minimum value of core_freq used for dynamic clocking.
disable_splash If set to 1, avoids the rainbow splash screen on boot.
force_turbo Disables dynamic cpufreq driver and all _freq_min settings. Voids Warranty.
gpu_mem GPU memory in megabytes. Sets the memory split between the ARM and GPU. ARM gets the remaining memory. Minimum value is 16 MB, Default value is 64 MB
initial_turbo Enables turbo mode from boot for the given value in seconds (up to 60) or until cpufreq sets a frequency. Default 0
over_voltage ARM/GPU core voltage adjust. Values above 6 are only allowed when force_turbo or current_limit_override are specified (which set the warranty bit).
sdram_freq Frequency of SDRAM in MHz
sdram_freq_min Minimum value of sdram_freq used for dynamic clocking.
temp_limit Overheat protection. Sets clocks and voltages to default when the SoC reaches this Celsius value. Setting this higher than default voids warranty. Default 85

Please share with your friends...
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  

1 comment

  1. I’m in the process of installing UniFi on a RasPi but will go to bed now (after 1AM) and finish tomorrow. Later I want to install it on an OrangePiPC if I can.
    Thanks for the info 🙂

Leave a Reply