Overclocking Jetson Nano CPU to 2 GHz and GPU to 1 GHz

The procedure is written and tested on a Jetson Nano with a JetPack 4.4, 4.5 and 4.6.1 [L4T 32.7.1]. Please check your version with jtop. Notice also the actual temperature of the Jetson Nano and the free space on the disk.

Checklist.

If your folder happens to be named kernel/kernel-5.10, you downloaded the wrong version. As mentioned earlier, JetPack 5.1 is not suitable for the Jetson Nano. Please download the correct version before continuing.

After successfully installing the modules, your screen will look like this.

The first line (#!/bin/bash) is a so-called shebang which let the script executed as bash shell.

The next line (sleep 15) holds the execution for 15 seconds. It turns out that the boot sequence first calls the rc.local script, which in its turn, call the overclock script. Next, the boot continues with filling the PLL's of the clock hardware and setup the clock governer. This action will cancel any previous instructions to the clock. In other words, the settings in overclock.sh has no bearing. The 15 second delay allows the boot sequence to set the clock registers first, where after the script can set the maximum clock speed permanently.

The third line defines the maximum CPU clock frequency, here 1900000 (kHz) or 1.9 GHz.

The last line dictates the maximum GPU frequency. In this case, 950000000 (Hz), which gives a clock rate of 950 MHz.

For those unfamiliar with rc.local, this script always runs at startup automatically when present in the /etc folder.

The first line is the shebang which let the script executed as bash shell. This line must be present if you expand an already existing rc.local on your Jetson Nano.

The next line calls the overclock script. Note the ampersand at the end of the line, which is crucial. It let the overclock script execute in a separate thread while continuing the execution. Remember, the overclock script expects within 15 seconds that the boot sequence is ready with the clock registers so it can set maximum frequency. Without the ampersand, rc.local will wait until the overclock script has finished before continuing.

After the restart, your maximum clock frequencies are activated, as you can see below.

Again, these maxima are not strict limits. It is more trail and error. With a simple text editor like nano, boundaries easily are altered.

Again, these maxima are not strict limits. It is more trail and error. With a simple text editor like nano, boundaries easily are altered. Please give reasonable figures.

Some last remarks. In the text, you read that the jetson_clocks script also can store and reload settings.

That's correct. Unfornuality the maximum clock speed is not supported.

The clock frequency on a Jetson Nano is very dynamic. In contrast to a Raspberry Pi where there are only two speeds (min and max), the Nano has lots of possible frequencies. Which one used depends on the task on hand and will be set by the so-called governer, all to keep power consumption as low as possible. Below the possible frequencies before overclocking.

And these are the frequencies after overclocking.

Note the commands. These are slightly different compared to the documentation.

By the way, the paragraph about making settings stick, does not apply in our case. The text refers to the governor, not the maximum clock frequency.

Somewhat confusing is the lscpu command. It gives you the maximum governer clock frequency found with the command cat /sys/.../scaling_available_frequencies. Not the actual limited value set by sys/.../scaling_max_freq, as can be seen below.

Use a new SD card. Old and worn out cards cause problems when the Jetson Nano is overclocked. They can crash the system when writes are stacked due to slow processing.