Highest Overclock RPi4

What is the highest any one has overclocked a RPi4 and run Risc OS, I’ve taken mine to 2100MHz with a 600MHz GPU Clock (as this supposedly improved Cache performance as it’s clock is tied to the GPU speed).

I’m interested as the system performance is alot better especially running apps such as Iris when browsing Javascript heavy pages.

How did you manage that overclock? What sort of cooling solution are you using, and how do you test for reliability? Were you certain that your overclock was stable?

In the file !boot.loader.config/txt add the lines:

over_voltage=6
arm_freq=2000
gpu_freq=600

Then used !CPUspeed to confirm the new clock speed and cpu temp.

Performance and stability were confirmed by running web browser benchmarks on iris, names speedometer 2.0 and web bench

My cooling is just small heat sinks on all chips and a small case with a built in fan running constantly, CPU temp didn’t go over 50C when running constantly at 2100MHz for over an hour.

The RPi4 is able to reliably overclock to 2000MHz and some can be pushed to 2500MHz, mine became unstable at 2300MHz and would randomly reboot so took it back to 2100MHz

The GPU should do 750, but I’m not sure you’d see much benefit under RISC OS.

The benefit of increasing the GPU clock is that the cache speed is tied to that of the GPU so you will see a modest improvement in performance but not significant

As RISCOS only uses one core of the four , it is possible that another core over clocks slightly higher. I don’t think currently it is possible to swap cores.