Overclocking "How to"??

[southpaw32]

I have a few different Raspberry Pis, so I figured I'd turn one into a Recalbox.

I'm running it on a Pi 400.

I usually overclock my RPis, by editing the /boot/config.txt file, but that doesn't seem to be working on Recalbox. For one, it says it can't write to the file. Once I got past that, I'm not seeing an change in CPU speed with "watch -n 2 vcgencmd measure_clock arm"

Do I edit "recalbox-config.txt" instead?

What am I missing here? I've search, but haven't been able to find a good "How to" for OCing Recalbox.

[Zing]

@southpaw32 For now, the place with the best information on overclocking is this post:
https://forum.recalbox.com/topic/21649/overclocking-pi4-with-recalbox-7

[southpaw32]

Thanks! I've got it figured out, so I'll post what I know.

Basically, it's the same as overclocking in RPi OS.

Edit the config file with: nano /boot/config.txt

I used SSH to login to my box, but you could edit that file with a text editor on another system as well.

On my Raspberry Pi 400 I used the following:
over_voltage=6
arm_freq=2200
gpu_freq=750
arm_freq_min=900

Raising the Minimum to 900 seems to make things a little smoother. I might try raising that some more later.

I was also having some audio stuttering in a couple of games so I adjusted:
audio_pwm_mode=2
Originally it was =514
I've also heard you can try a =0

You can verify your speed with: watch -n 2 vcgencmd measure_clock arm
That shows you the speed the CPU is running at ever 2 seconds.

Overall, it's just like overclocking in Raspberry Pi OS

[LapinFou]

@southpaw32 said in Overclocking "How to"??:

On my Raspberry Pi 400 I used the following:
over_voltage=6
arm_freq=2200
gpu_freq=750
arm_freq_min=900

You should first try with arm_freq = 2000. I read than a greater value could in fact underclock the CPU instead overclocking it.
With this setting (2GHz), I got about 10/15% more FPS with the Dreamcast emulator.

[barbudreadmon]

@LapinFou said in Overclocking "How to"??:

I read than a greater value could in fact underclock the CPU instead overclocking it

That's probably because when pi reach thermal threshold, it'll downclock to reduce the temp, it can happen on any pi with any freq, so always make sure your pi is properly cooled

[LapinFou]

@barbudreadmon said in Overclocking "How to"??:

@LapinFou said in Overclocking "How to"??:

I read than a greater value could in fact underclock the CPU instead overclocking it

That's probably because when pi reach thermal threshold, it'll downclock to reduce the temp, it can happen on any pi with any freq, so always make sure your pi is properly cooled

Not on my PI4. I'm using this Ice Tower. The CPU is dead cold.
From what I read, it is more an OS issue. Overclocking higher than 2GHz doesn't seem to work well.