Raspberry Pi 5 Desktop Mini PC: Overclocking

This is a multi-part blog looking at a Raspberry Pi 5 running Linux as a desktop computer.

In my previous article in this series, I ran a set of benchmarking comparing the Raspberry Pi 5 to an Intel N100 Mini PC. This article repeats some of the benchmarks but this time includes additional results by overclocking the Pi 5 by varying degrees.

To overclock the Pi 5, edit /boot/firmware/config.txt and add a few additional lines. Here’s an example to overclock the core frequency to 2.6 GHz, set the VideoCore VII core frequency to 900 MHz, and increasing the voltage limit.

arm_freq=2600
gpu_freq=900
over_voltage=2

It’s probably better to use over_voltage_delta rather than over_voltage but it makes no difference to the benchmark results.

Here’s a table showing the overclocking frequencies used in the charts below.

I’m only going to run a few benchmarks as this gives sufficient information to assess how an overclocked Pi 5 compares to the N100 Mini PC. These benchmarks only test the CPU.

$ phoronix-test-suite benchmark smallpt

Smallpt is a C++ global illumination renderer written in less than 100 lines of code. Global illumination is done via unbiased Monte Carlo path tracing and there is multi-threading support via the OpenMP library.

Even the non-overclocked Pi 5 beats the N100 in this test. But with overclocking, the margin increases significantly. Performance scales decently.

$ phoronix-test-suite benchmark compress-pbzip2

This test measures the time needed to compress a file (a .tar package of the Linux kernel source code) using BZIP2 compression.

The N100 still surpasses an overclocked Raspberry Pi 5 by a country mile. Even if I pushed the Pi 5 above 3.0 GHz, it’ll get nowhere near the N100 for this benchmark.

$ phoronix-test-suite benchmark coremark

Coremark is a benchmark that measures the performance of central processing units (CPU) used in embedded systems.

A significantly overclocked Pi 5 puts in a decent result getting very close to the N100’s performance.

Summary

The benchmarks demonstrate that the Pi 5 is competitive with an Intel N100 and will make a capable desktop machine.

My board gives a stable overclock at 3.0 GHz. I didn’t try any higher but given I’m using a Pironman 5 case which has case fans and a decent heatsink/fan cooler, I could probably overclock even more. The Pi 5 temperature peaks at only 57.9°C under full load even overclocking at 3.0 GHz. That’s at a room temperature of 20.7°C.

A few things to bear in mind:

• Overclocking increases power consumption, leading to higher heat output. Make sure your Pi 5 has adequate cooling when overclocking. Monitor the CPU temperature using vcgencmd measure_temp.
• Overclocking can cause system crashes. Use the s-tui program to stress the machine. At the same time, the program monitors the temperature in real time. The Pi 5 will throttle when the temperature reaches 85°C.

All articles in this series: