Reply To: PSP almost perfect but frequent io transfers cause freeze

Welcome Page Forums RetroPie Project New to RetroPie? Start Here! PSP almost perfect but frequent io transfers cause freeze Reply To: PSP almost perfect but frequent io transfers cause freeze

#120410
Profile photo of joyrider3774
joyrider3774
Participant

you have to watch out with overclocking and the pi3 not because of the usual precautions but because the PI starts throtteling the cpu speed (down) when it reaches 80°C if it reaches 85°C or above it will throttle cpu speed to 600mhz (half of the speed) and i know they are going to let it throttle even lower (in a test firmware they did this already)

the pi3 reaches these tempratues fairly easy with some benchmark tools / cpu stressing tools and i noticed when i was running tekken 3 (actually playing) for a while i had tempratues near 75-80°C this is while the pi3 just sits in my picade so it has more air then in normal closed enclosure.

if you overlock you will reach 80-85°C and you will have lower speed then when you would not reach those temps. It happend with me with ppsspp, did not test other emulators but i guess it could happen with N64 depending on the game as well. this was wit a bit of overlocking as well as turbo mode etc, but it depends on the game and if the pi struggles with the game or not.

Using heatsinks probably doesn’t help much (it will make it go slower to those tempratrues and might give you 0-2°C diffrence, but if you are stressing the cpu it will reach those temps eventually) unless your also using a fan to blow cool air through the heatsink that probably helps a lot at least a lot more than just using a heatsink.

I created a simple script to show me the tempratures as well as the cpu speed in a loop. It’s based on code i found in retropie’s (login details info) script.

basically you put this in a file and chmod the file with for exmaple chmod 777 filename

then you can execute it.

The way you should execute it is by opening an ssh connection and let it run there and then start testing playing games / overlocking etc. you can then easilly see the cpu throttling if it eaches those temps, you exit the script by pressing ctrl+c

edit: if you want to see it reach those tempratures and throtteling sudo apt-get install stress (i think it was stress) and then run it with stress -c 4 that will use 4 threads to keep the cpu busy and with my pi3 i can easily reach those temps then


    #!/bin/bash
    function cputemp() {
    local cpuTempC
    local cpuTempF
    local gpuTempC
    local gpuTempF
    if [[ -f "/sys/class/thermal/thermal_zone0/temp" ]]; then
            cpuTempC=$(($(cat /sys/class/thermal/thermal_zone0/temp)/1000)) && cpuTempF=$((cpuTempC*9/5+32))
    fi
    if [[ -f "/opt/vc/bin/vcgencmd" ]]; then
            if gpuTempC=$(/opt/vc/bin/vcgencmd measure_temp); then
                 gpuTempC=${gpuTempC:5:2}
                 gpuTempF=$((gpuTempC*9/5+32))
            else
                 gpuTempC=""
            fi
            cpuFreq=$(/opt/vc/bin/vcgencmd measure_clock arm)
    fi

    echo "cpu temp=$cpuTempC°C gpu temp=$gpuTempC°C $cpuFreq"
    }

    while true; do cputemp; sleep 2; done;

Skip to toolbar