56 LXF257 December 2019 http://www.linuxformat.comTUTORIALS Cooling your Pi
How to keep your
Raspberry Pi 4 cool
Les Pounder shows us how to keep the new Raspberry Pi 4 cool, even
under heavy workloads, using bolt-ons.
Les Pounder
is a freelance
maker who
works with
organisations
across the world.T
COOLERS
OUR
EXPERTThe Raspberry
Pi 4 can get
quite hot very
quickly. Children
should not
directly touch
the CPU as they
may get a small
burn. If using
the Pi 4 with
children, ensure
that it’s in a
case, and that
it has adequate
cooling.generating more heat as their speed increased,
heatsinks were no longer enough and fans were needed
to whisk the heat away from the CPU. It has now
become the norm for PCs to have many fans to keep
everything cool, and with the Pi 4 now running a more
powerful CPU, the need for active cooling has arrived.
But which is best for our Raspberry Pi 4? Let’s find out!Hot stuff
We used a Raspberry Pi 4 running the latest version of
Raspbian, and with the firmware updated to the latest
available. For each test the Pi was allowed to rest and
stabilise temperature for five minutes before a test was
run. Each cooling unit was used with the stock
equipment/accessories which it came with.
The test involved running Sysbench to verify prime
numbers between 2 and 50,000, and used all four
cores of the CPU. The data was collected using a
Python script which ran every minute and collected the
current time, CPU temperature and CPU speed. This
was then saved to a CSV file and edited in a
spreadsheet. We also looked at whether the cooling
systems gave decent access to the GPIO pins, Camerahe Raspberry Pi has seen great increases in
CPU speed since 2012. From a single-core
700MHz CPU to the latest Pi 4 and a 1.5GHz
quad-core CPU is quite a difference, and with this
increase in power there is an inevitable increase in heat.
The Raspberry Pi 4 has a rather warm CPU: a stock Pi
can idle at 39°C, and under extended heavy load it can
reach up to 80°C! There are now many companies
offering their version of a cooling system to help
prolong the life of the Pi 4 and stop our fingers getting
burnt. But which is the most effective? Which is the
cheapest? And do we need passive or active cooling?Passive vs active cooling
Passive cooling is when a CPU is cooled using a
heatsink or pipe, which draws away the heat from the
CPU to a series of thin metals fins that are designed to
offer the most surface area from which the heat can
dissipate. CPUs have used heatsinks since the late 386
devices, and this was enough for most CPUs.
But with the rise of the Pentium era, extra cooling
was required and this is where active cooling became
the norm. With the more powerful Pentium CPUsIt may look like a griddle pan,
but the Pimoroni Aluminium
case offered acceptable cooling
for low-noise projects.56 LXF257 December 2019 http://www.linuxformat.com
TUTORIALS Cooling your Pi
How to keep your
Raspberry Pi 4 cool
LesPoundershows us how to keep the new Raspberry Pi 4 cool, even
underheavyworkloads, using bolt-ons.
LesPounder
is a freelance
maker who
works with
organisations
across the world.
T
COOLERS
OUR
EXPERTTheRaspberry
Pi4 canget
quitehotvery
quickly.Children
shouldnot
directlytouch
theCPUasthey
maygeta small
burn.If using
thePi4 with
children,ensure
thatit’sina
case,andthat
it hasadequate
cooling.generating more heat as their speed increased,
heatsinks were no longer enough and fans were needed
to whisk the heat away from the CPU. It has now
become the norm for PCs to have many fans to keep
everything cool, and with the Pi 4 now running a more
powerful CPU, the need for active cooling has arrived.
But which is best for our Raspberry Pi 4? Let’s find out!Hot stuff
We used a Raspberry Pi 4 running the latest version of
Raspbian, and with the firmware updated to the latest
available. For each test the Pi was allowed to rest and
stabilise temperature for five minutes before a test was
run. Each cooling unit was used with the stock
equipment/accessories which it came with.
The test involved running Sysbench to verify prime
numbers between 2 and 50,000, and used all four
cores of the CPU. The data was collected using a
Python script which ran every minute and collected the
current time, CPU temperature and CPU speed. This
was then saved to a CSV file and edited in a
spreadsheet. We also looked at whether the cooling
systems gave decent access to the GPIO pins, Camerahe Raspberry Pi has seen great increases in
CPU speed since 2012. From a single-core
700MHz CPU to the latest Pi 4 and a 1.5GHz
quad-core CPU is quite a difference, and with this
increase in power there is an inevitable increase in heat.
The Raspberry Pi 4 has a rather warm CPU: a stock Pi
can idle at 39°C, and under extended heavy load it can
reach up to 80°C! There are now many companies
offering their version of a cooling system to help
prolong the life of the Pi 4 and stop our fingers getting
burnt. But which is the most effective? Which is the
cheapest? And do we need passive or active cooling?Passive vs active cooling
Passive cooling is when a CPU is cooled using a
heatsink or pipe, which draws away the heat from the
CPU to a series of thin metals fins that are designed to
offer the most surface area from which the heat can
dissipate. CPUs have used heatsinks since the late 386
devices, and this was enough for most CPUs.
But with the rise of the Pentium era, extra cooling
was required and this is where active cooling became
the norm. With the more powerful Pentium CPUsIt may look like a griddle pan,
but the Pimoroni Aluminium
case offered acceptable cooling
for low-noise projects.