NVIDIA Jetson Xavier - Performance Tuning by Setting CPU, GPU, and Frequency Values Manually

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Manage CPU State

The Tegra will always boot from one CPU denominated the master CPU, this cannot be turned off, and all other CPUs can be turned off.

To manually turn on/off slave CPUs

1) Run the following command to turn on the slave CPU:

CPU=cpu1 #The number can be changed from 1-7
echo 1 > /sys/devices/system/cpu/$CPU/online

2) Run the following command to turn the slave CPU off:

echo 0 > /sys/devices/system/cpu/$CPU/online

To check the CPU state run the following commands:

cat /sys/devices/system/cpu/$CPU/online

3D Frequency Scaling

Frequency scaling allows the Tegra to change the CPU frequency according to the load in order to reduce power consumption, 3D frequency scaling is enabled by default.

To disable 3D frequency scaling run the following command:

echo 0 >  /sys/devices/17000000.gv11b/enable_3d_scaling

To enable 3D frequency scaling run the following command:

echo 1 >  /sys/devices/17000000.gv11b/enable_3d_scaling

Change CPU Frequency

To print the CPU lower boundary, upper boundary, and current frequency run the following commands:

CPU=cpu1 #The number can be changed
cat /sys/devices/system/cpu/$CPU/cpufreq/cpuinfo_min_freq
cat /sys/devices/system/cpu/$CPU/cpufreq/cpuinfo_max_freq
cat /sys/devices/system/cpu/$CPU/cpufreq/cpuinfo_cur_freq

To change the CPU upper boundary run the following command:

CPU_FREQ=115200
CPU=cpu1 #The number can be changed
echo $CPU_FREQ > /sys/devices/system/cpu/$CPU/cpufreq/scaling_max_freq

To change the CPU lower boundary run the following command:

CPU_FREQ=2265600
CPU=cpu1 #The number can be changed
echo $CPU_FREQ > /sys/devices/system/cpu/$CPU/cpufreq/scaling_min_freq

To set the static CPU frequency run the following commands:

CPU_FREQ=2265600
CPU=cpu1 #The number can be changed
echo $CPU_FREQ > /sys/devices/system/cpu/$CPU/cpufreq/scaling_min_freq
echo $CPU_FREQ > /sys/devices/system/cpu/$CPU/cpufreq/scaling_max_freq

Where CPU_FREQ must be among the values in /sys/devices/system/cpu/$CPU/cpufreq/scaling_available_frequencies

Change GPU Frequency

To print the GPU lower boundary, upper boundary, and current frequency run the following commands:

cat /sys/devices/17000000.gv11b/devfreq/17000000.gv11b/min_freq
cat /sys/devices/17000000.gv11b/devfreq/17000000.gv11b/max_freq
cat /sys/devices/17000000.gv11b/devfreq/17000000.gv11b/cur_freq

To change the GPU upper boundary run the following command:

GPU_FREQ=675750000
echo $GPU_FREQ > /sys/devices/17000000.gv11b/devfreq/17000000.gv11b/max_freq

To change the GPU lower boundary run the following command:

GPU_FREQ=114750000
echo $GPU_FREQ > /sys/devices/17000000.gv11b/devfreq/17000000.gv11b/min_freq

To set the static GPU frequency run the following command:

GPU_FREQ=675750000
echo $GPU_FREQ > /sys/devices/17000000.gv11b/devfreq/17000000.gv11b/min_freq
echo $GPU_FREQ > /sys/devices/17000000.gv11b/devfreq/17000000.gv11b/max_freq

Where GPU_FREQ is the value available in: /sys/devices/17000000.gv11b/devfreq/17000000.gv11b/available_frequencies

Change Memory Frequency

echo 1 > /sys/kernel/debug/bpmp/debug/clk/emc/mrq_rate_locked
echo 1 > /sys/kernel/debug/bpmp/debug/clk/emc/state
echo 665600000 > /sys/kernel/debug/bpmp/debug/clk/emc/rate

To print the EMC lower boundary, upper boundary, and current frequency run the following commands:

cat /sys/kernel/debug/bpmp/debug/clk/emc/min_rate
cat /sys/kernel/debug/bpmp/debug/clk/emc/max_rate
cat /sys/kernel/debug/bpmp/debug/clk/emc/rate

To change the EMC upper boundary run the following command:

EMC_FREQ=2133000000
echo $EMC_FREQ > /sys/kernel/debug/bpmp/debug/clk/emc/max_rate

To change the EMC lower boundary run the following command:

EMC_FREQ=204000000
echo $EMC_FREQ > /sys/kernel/debug/bpmp/debug/clk/emc/min_rate

To set static EMC frequency run the following commands:

EMC_FREQ=2133000000
echo 1 > /sys/kernel/debug/bpmp/debug/clk/emc/mrq_rate_locked
echo 1 > /sys/kernel/debug/bpmp/debug/clk/emc/state
echo $EMC_FREQ > /sys/kernel/debug/bpmp/debug/clk/emc/rate

Where EMC_FREQ in kHz is the value available in: /sys/kernel/debug/bpmp/debug/emc/tables/regular/



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