RaspberryPi 4 comes with 1.5GHz stock frequency. Not bad, but what if we could push it a bit higher? The problem is that the Pi4 is already running hot at stock (around 50C) and using just passive cooling will not do much for it.
Adding a fan will definitely help, but just how much exactly?
For stress testing the Pi4, we used the guide posted here
Results of the test from the console:
No cooling | No Overclock | 1 Amp
This is an image of the Pi4, running on stock settings and executing cpuburn-a53.s
As you can see, its running hot. So how can we improve the results AND overclock the Pi4 while maintaining stability?
For this purpose we need a case with a fan, and a power supply of 2Amp or more. We had experience with the Pi3 and 30mm fans for cooling so we thought we may start from scratch and design a new case design with a more targeted airflow to achieve our goal. The result was very promising! Below some pics from the case
The secret of the case is on the inside. It has a skirt under the fan, to better direct the airflow to the CPU and other components that were getting hot. Notice also the exit vent on the back, just above the SD card slot. This helps the hot air exit fast as you will see later.
We are using a 40mm generic fan, 5V 0.1A to keep the budget low and the energy consumption within the limits of the PSU.
We are running the stress test again
A53 Burn test | CRIO Case with 40mm fan | Overclocked 2Ghz | 2.1 Amp
Lets see the thermals now:
Obviously we can no longer see inside the case but we can read the CPU tem from the stress test and we can of course see the hot air exiting the case from the rear vent, the GPIO slot and some from the gap on the usb ports.
Conclusion: We can run the Pi4 at 2GHz stable, and maintain temperatures below the 80C throttling levels. Obviously this temperature is at 100% CPU load. Idling it runs at a cool 50C.
Ultimately, you can run it at 1,7Ghz and get much lower thermals
A53 Burn test | CRIO FAN Case | Overclocked 1,7GHz | 1.7 Amp
The trade-off is of course the noise from the fan. We clocked it at 45 dBa at 50cm from the Pi and at 40dBa at 1meter away. Not bad, but you don’t want it to be running next to you in your living room! A Noctua 40mm fan will do even better for thermals while keeping the noise level lower.
We hope you like our CRIO case and will get one yourselves 😉
All images are copyright of INUX3D (c) 2019