Is there any way in debian/ubuntu to put CPU under load until it reaches a certain temperature?-CodePudding

I need this for some stress testing with my CPU. It uses Linux-Debian/Ubuntu OS and I was wondering if there's any way that I could put it under load until it reaches a certain temperature.

Are there any commands, packages or bash scripts for this?

Any help is appreciated!

CodePudding user response：

Download Prime95 from here or use any other CPU-Stress test that works under Debian/Ubuntu.

Get the following package:

sudo apt-get install lm-sensors

Start the sensors in terminal and update continously:

watch sensors

Now start Prime95 or your preferred stress-test and you can see cpu-temp inside terminal. Stop Stress test if cpu-temp exceeds your desired temperature. (modern cpu's are lowering clockspeed or shutting down automatically before damage from overheating is taken)

CodePudding user response：

I don't know of an existing software package (other than prime95 for max heating), but it's relatively easy to create loops with differing amounts of heat, like awk 'BEGIN{for(i=0;i<100000000;i ){}}' keeps a CPU busy for a while making some heat.

See How to write x86 assembly code to check the effect of temperature on the performance of the processor for some suggestions on creating loops that heat the CPU more vs. less.

To hit a target temperature, you'll need to write some code to implement control loop that reads the temperature (and the direction it's trending) and adjusts the load by starting/stopping threads, or changing up how power-intensive each thread is. Without this feedback, you won't consistently hit a given CPU temperature; the actual temperature for an fixed workload will depend on ambient temp, how dusty your heat-sink is, and how the BIOS manages your fan speeds, etc.

Perhaps your CPU-heating threads could branch on a global atomic variable in an outer loop, so you can change what work they do by changing a variable. e.g. 2 FMAs per clock, 1 FMA per clock, FMAs bottlenecked by latency (so 1 per 4 clocks), or just integer work, or a loop just running pause instructions, so it does the minimum. Or 256-bit vs. 128-bit vs. scalar.

Perhaps also changing your EPP setting (on Intel Skylake or newer) with sudo sh -c 'for i in /sys/devices/system/cpu/cpufreq/policy[0-9]*/energy_performance_preference;do echo performance > "$i";done' or balance_performance or balance_power (emphasize power-saving); these may affect what turbo clock speeds your CPU chooses to run at.

Read the temperature with lm-sensors, or by reading from the "coretemp" kernel driver directly on modern x86 hardware, e.g. /sys/class/hwmon/hwmon3/temp1_input reads as 36000 for 36 degrees C.

$ grep . /sys/class/hwmon/hwmon3/*
/sys/class/hwmon/hwmon3/name:coretemp

/sys/class/hwmon/hwmon3/temp1_input:36000
/sys/class/hwmon/hwmon3/temp1_label:Package id 0

/sys/class/hwmon/hwmon3/temp2_input:35000
/sys/class/hwmon/hwmon3/temp2_label:Core 0

/sys/class/hwmon/hwmon3/temp5_input:33000
/sys/class/hwmon/hwmon3/temp5_label:Core 3

I'm not sure if the temperature is available directly to user-space without the kernel's help, e.g. via CPUID, on Intel or AMD.