undo my experiement with overclocking....

Amishgamer

Here's what I got...

Pi 3B+
The 2.5a power supply that came in the cana kit
Retropie v 4.4
Wii U pro controller connected via bluetooth, no other usb devices connected
Built From Pre made SD Image on RetroPie website

I did a brief experiment into the world of overclocking. I put the following into my config.txt file...

arm_freq=1575
gpu_freq=500
core_freq=500
sdram_freq=500
sdram_schmoo=0x02000020
over_voltage=6
sdram_over_voltage=2

But, after feeling how physically warm my pi was, despite having a massively huge kintaro heatsink, I decided...meh, what do I need it for? Most, if not all, the games I play work fine, anyway. So, I undid it. I went to the config.txt file and I commented out all those lines.

By running this command...

sudo cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq

I confirmed my pi is back to the 1.4 GHz that I started at. Alright, good.

While I was overclocking, I also entered the following command...

echo "performance" |sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

Before I entered this command, every time I did a sysbench, it came back around 70 seconds. Since I entered the command, both overclocked and standard clock, it comes back around 93 seconds. I'm assuming it's because my pi is idle and it's taking it easy or something, even though I'm running sysbench. But, I'd still like to undo that command so that sysbench will return to running somewhere in the 70's.

How do I undo the

echo "performance" |sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

command?

Thanks in advance?

mitu

@Amishgamer said in undo my experiement with overclocking....:

How do I undo the
echo "performance" |sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
command?

That only has effect until the next reboot, so you could reboot your PI.

quicksilver

@mitu so the CPU governor is reset to default each time the pi is rebooted?

mitu

@quicksilver If you change it with the method posted above, yes, the sysfs modifications via echo are not persistent.

Amishgamer

I'm not doubint you. But, I am wondering then why is my sysbench readings still coming in >90 seconds when they should be in the 70's.

Any suggestions? I hate to restart building my retropie. It's finally almost the way I like it :D

mitu

@Amishgamer Who knows ? Do you think it matters ?

Amishgamer

Well, earlier today just browsing the Emulationstation got a little choppy...

edmaul69

@Amishgamer emulationstation gets choppy if you have a bunch of systems on the pi. Turning off the help menu fixes it. Not sure if you do or not.

Efriim

@Amishgamer
How do you invoke sysbench?

Amishgamer

sysbench --test=cpu --cpu-max-prime=20000 --num-threads=4 run

Efriim

@Amishgamer
If i'm reading it right, pi3b+
my overclocked total time is 72 and 75 seconds.
and default gives me 81 seconds.

I don't know what could be adding to get >90s

Efriim

@Amishgamer
It is likely that your pi was throttling to 1200mhz
setting mine to 1200mhz returned 95s sysbench.
while it used to do this at 70c it has been changed to 60c degrees
if you have a fan or heatsink make sure they are properly fixed.
if you only have a heatsink and no fan then this temperature is normal, and the throttling level can be increased by setting
temp_soft_limit=70
to config.txt

here are some commands to read from vcgencmd the current voltage and frequencies
for src in arm core h264 isp v3d; do echo -e "$src:\t$(vcgencmd measure_clock $src)"; done

for id in core sdram_p sdram_i sdram_c ; do echo -e "$id:\t$(vcgencmd measure_volts $id)"; done
and read the systems boot time, userspace time completion can vary by up to 5 - 90 seconds depending on the last shutdown and if the system thinks it needs a filesystem check or on usb drives.
systemd-analyze

I added them to a script to be able to execute all together

#!/bin/bash
for id in core sdram_p sdram_i sdram_c ; do echo -e "$id:\t$(vcgencmd measure_volts $id)"; done
for src in arm core h264 isp v3d; do echo -e "$src:\t$(vcgencmd measure_clock $src)"; done
cpuTemp0=$(cat /sys/class/thermal/thermal_zone0/temp)
cpuTemp1=$(($cpuTemp0/1000))
cpuTemp2=$(($cpuTemp0/100))
cpuTempM=$(($cpuTemp2 % $cpuTemp1))
echo CPU temp"="$cpuTemp1"."$cpuTempM"'C"
echo GPU $(/opt/vc/bin/vcgencmd measure_temp)
systemd-analyze