http://www.techradar.com/pro/linux December 2019 LXF257 59Cooling your Pi TUTORIALS
recommended limits, and overclocking a Raspberry Pi
is quite simple – but it should only be attempted if you
are prepared to accept that you may damage or break
your Pi. Don’t attempt to overclock without active
cooling! For our overclock we used the 52Pi Ice Tower
and some Arctic Silver thermal paste.
To overclock a Raspberry Pi 4, first open a terminal
and ensure that your software is up to date.
$ sudo apt update
$ sudo apt upgrade
The next step ensures that the firmware on your Pi 4
is up to date, as we need the latest version in order to
overclock successfully.
$ sudo rpi-update
When done, reboot your Pi to ensure that changes
are made correctly. To set the overclock for the Pi,
open a terminal and type the following to edit a
configuration file.
$ sudo nano /boot/config.txt
Using the arrow keys, scroll to the bottom of the file
and create a new line, then enter the following to set the
voltage and CPU speed.
over_voltage=4
arm_freq=2000
To save and exit nano, press Ctrl+X, and when asked
to save, press Y and then Enter. Reboot the Pi for the
overlock to take effect. When the Pi has rebooted, open
a terminal and type the following to see the currentCPU speed, which at idle is around 600MHz:
sudo watch cat /sys/devices/system/cpu/cpu0/
cpufreq/cpuinfo_cur_freq
How can we push the Pi to use the new overclocked
speed? Via a tool called Sysbench, we can instruct the
Pi to confirm prime numbers from 2 upwards, so let’s
ask the Pi to confirm all of the prime numbers from 2 to
50,000. For this we shall use all four cores (threads) of
the CPU to ensure that the Pi is maximised. In another
terminal, type:
$ sysbench --test=cpu --cpu-max-prime=50000 --num-
threads=4 run
Now watch the original terminal, which will update
every two seconds to show the current CPU speed.
Under load you shoule see the CPU speed shoot up to
2GHz – and hopefully stay there without crashing due
to overheating.
Cooling your Raspberry Pi 4 may not be essential
for day-to-day use, but for those that wish to push the
silicon and get the most from their Pi, it is absolutely
essential. As always, take great care when using cooling
units with your Pi 4, ensure that they are fitted correctly
and if they are made of metal, that they are not in
contact with electronics or power circuitry.KEEP COOL GETTING LXF... Subscribe now at http://bit.ly/LinuxFormat
THERMAL PADS VS THERMAL PASTE
The 486 and early Pentium chips ushered in cooling, and the heat
generated from a CPU needed to be removed as quickly as possible.
Thermally conductive materials were required, and with this the
thermal pad was factory-applied. We remember attaching the cooling
to our first 1GHz AMD Athlon CPU and playing a game... but we forgot
the thermal pad, and the CPU quickly cooked itself to death.
Thermal pads enabled anyone to simply place the cooling unit on
the CPU and get on with building the PC. But if you need to pull more
heat from a CPU, we can use a thermally conductive liquid: a paste.
Thermal paste is available in many different combinations and
various cooling claims, but typically it’s cheap and offers better
conductivity than a pad.
The problem is that thermal paste is a little tricky to apply if you’re
new to PC building. Just remember that a small blob goes a long way,
as the paste spreads out when heated. On our Raspberry Pi 4 with
the 52 Pi Ice Tower cooler we used a rather cheap Arctic Silver 5
compound, and applied a 5mm blob to the CPU. With that small
amount we dropped the CPU temperature considerably.CoolerIdle Full Load for
Four MinutesPrice WebsiteStock 39°C65°C N/A http://www.raspberrypi.org
Jun_Electronic 37°C47°C£18.99smile.amazon.co.uk/gp/product/B07WHGK1ZD/
Fan Shim (constant) 29°C45°C £9.60 http://bit.ly/lxf257shim
Fan Shim (software-
controlled fan)37°C63°C £9.60 http://bit.ly/lxf257shim52 Pi Ice Tower 31°C45°C£19.99smile.amazon.co.uk/gp/product/B07V35V1CH/
GeeekPi Aluminium 37°C56°C£14.99smile.amazon.co.uk/gp/product/B07VMRG26Y/
Pimoroni Aluminium
Case (passive)44°C63°C£12http://bit.ly/lxf257pimoroniThe GeeekPi case is made from aluminium, but it requires further
refinement to make it worthwhile. It’s a little too low-cost to prove
itself useful and safe for long-term projects.5556Decmbr rb6c2019b21showu December 2019 LXF257 59
Cooling your Pi TUTORIALS
recommended limits, and overclocking a Raspberry Pi
is quite simple – but it should only be attempted if you
are prepared to accept that you may damage or break
your Pi. Don’t attempt to overclock without active
cooling! For our overclock we used the 52Pi Ice Tower
and some Arctic Silver thermal paste.
To overclock a Raspberry Pi 4, first open a terminal
and ensure that your software is up to date.
$ sudo apt update
$ sudo apt upgrade
The next step ensures that the firmware on your Pi 4
is up to date, as we need the latest version in order to
overclock successfully.
$ sudo rpi-update
When done, reboot your Pi to ensure that changes
are made correctly. To set the overclock for the Pi,
open a terminal and type the following to edit a
configuration file.
$ sudo nano /boot/config.txt
Using the arrow keys, scroll to the bottom of the file
and create a new line, then enter the following to set the
voltage and CPU speed.
over_voltage=4
arm_freq=2000
To save and exit nano, press Ctrl+X, and when asked
to save, press Y and then Enter. Reboot the Pi for the
overlock to take effect. When the Pi has rebooted, open
a terminal and type the following to see the current
CPU speed, which at idle is around 600MHz:
sudo watch cat /sys/devices/system/cpu/cpu0/
cpufreq/cpuinfo_cur_freq
How can we push the Pi to use the new overclocked
speed? Via a tool called Sysbench, we can instruct the
Pi to confirm prime numbers from 2 upwards, so let’s
ask the Pi to confirm all of the prime numbers from 2 to
50,000. For this we shall use all four cores (threads) of
the CPU to ensure that the Pi is maximised. In another
terminal, type:
$ sysbench --test=cpu --cpu-max-prime=50000 --num-
threads=4 run
Now watch the original terminal, which will update
every two seconds to show the current CPU speed.
Under load you shoule see the CPU speed shoot up to
2GHz – and hopefully stay there without crashing due
to overheating.
Cooling your Raspberry Pi 4 may not be essential
for day-to-day use, but for those that wish to push the
silicon and get the most from their Pi, it is absolutely
essential. As always, take great care when using cooling
units with your Pi 4, ensure that they are fitted correctly
and if they are made of metal, that they are not in
contact with electronics or power circuitry.KEEP COOL GETTING LXF... Subscribe now at http://bit.ly/LinuxFormat
THERMAL PADS VS THERMAL PASTE
The 486 and early Pentium chips ushered in cooling, and the heat
generated from a CPU needed to be removed as quickly as possible.
Thermally conductive materials were required, and with this the
thermal pad was factory-applied. We remember attaching the cooling
to our first 1GHz AMD Athlon CPU and playing a game... but we forgot
the thermal pad, and the CPU quickly cooked itself to death.
Thermal pads enabled anyone to simply place the cooling unit on
the CPU and get on with building the PC. But if you need to pull more
heat from a CPU, we can use a thermally conductive liquid: a paste.
Thermal paste is available in many different combinations and
various cooling claims, but typically it’s cheap and offers better
conductivity than a pad.
The problem is that thermal paste is a little tricky to apply if you’re
new to PC building. Just remember that a small blob goes a long way,
as the paste spreads out when heated. On our Raspberry Pi 4 with
the 52 Pi Ice Tower cooler we used a rather cheap Arctic Silver 5
compound, and applied a 5mm blob to the CPU. With that small
amount we dropped the CPU temperature considerably.CoolerIdle Full Load for
Four MinutesPrice WebsiteStock 39°C65°C N/A http://www.raspberrypi.org
Jun_Electronic 37°C47°C£18.99smile.amazon.co.uk/gp/product/B07WHGK1ZD/
Fan Shim (constant) 29°C45°C £9.60 http://bit.ly/lxf257shim
Fan Shim (software-
controlled fan)37°C63°C £9.60 http://bit.ly/lxf257shim52 Pi Ice Tower 31°C45°C£19.99smile.amazon.co.uk/gp/product/B07V35V1CH/
GeeekPi Aluminium 37°C56°C£14.99smile.amazon.co.uk/gp/product/B07VMRG26Y/
Pimoroni Aluminium
Case (passive)44°C63°C£12http://bit.ly/lxf257pimoroniThe GeeekPi case is made from aluminium, but it requires further
refinement to make it worthwhile. It’s a little too low-cost to prove
itself useful and safe for long-term projects.