overclocking.md

Overclocking

It is possible to slightly bump Rock64 specs.

Keep in mind that this can break your board.

CPU

Currently CPU is clocked at 1296MHz max. Feel free to check:

Check frequency and health

You can quickly run rock64 diagnostics to see most vital parameters of your board (CPU frequency, temperature of SoC, and CPU usage):

rock64_diagnostics.sh -m

You can always quickly check current actual CPU frequency:

cat /sys/devices/system/cpu/cpufreq/policy0/cpuinfo_cur_freq

Add additional operating point (dynamically)

Use dt overlays to add additional 1.392GHz operating point (requires at least 0.6.13):

enable_dtoverlay 1398mhz cpu0-opp-table okay "opp-1392000000 {
            opp-hz = /bits/ 64 <1392000000>;
            opp-microvolt = <1350000>;
            opp-microvolt-L0 = <1350000>;
            opp-microvolt-L1 = <1325000>;
            clock-latency-ns = <40000>;
}"

Then, force to reload frequency table:

echo cpufreq-dt > /sys/bus/platform/drivers/cpufreq-dt/unbind
echo cpufreq-dt > /sys/bus/platform/drivers/cpufreq-dt/bind

At very least verify that a new operating point is loaded:

cat /sys/devices/system/cpu/cpufreq/policy0/scaling_available_frequencies 
408000 600000 816000 1008000 1200000 1296000 1392000

Stability testing

With every overclocking it is important to perform stability testing. The best for that is cpuburn:

cd /usr/src
git clone https://github.com/ssvb/cpuburn-arm
cd cpuburn-arm
gcc -o cpuburn-a53 cpuburn-a53.S
./cpuburn-a53

On other terminal session run:

rock64_diagnostics.sh -m

GPU

Currently GPU is clocked at 500MHz max. Feel free to check:

cat /sys/class/devfreq/ff300000.gpu/load
cat /sys/class/devfreq/ff300000.gpu/trans_stat

Video Decoder

Currently video decoder is clocked at 500MHz max. Feel free to check (it crashes as of 0.6.28):

cat /sys/class/devfreq/ff360000.rkvdec/load
cat /sys/class/devfreq/ff360000.rkvdec/trans_stat

RAM

The Rock64 boots with DDR333 configured. This is the most safe configuration, but then immediately switches to DDR786MHz mode.

It is possible to overclock the DRAM slightly by using:

echo 933000000 > /sys/bus/platform/drivers/rockchip-dmc/dmc/devfreq/dmc/max_freq
echo performance > /sys/bus/platform/drivers/rockchip-dmc/dmc/devfreq/dmc/governor

You can see actually assigned speed with:

cat /sys/bus/platform/drivers/rockchip-dmc/dmc/devfreq/dmc/load
cat /sys/bus/platform/drivers/rockchip-dmc/dmc/devfreq/dmc/trans_stat

This works only on 4.4 kernel, and has negative effects on mainline kernel, as mainline does not support dynamic memory controller.