I would like to measure latencies during high cpu usage but I don't have benchmarking tools like stress and I can't install them.

Which operations do you recommend to put the cpu under intense load? I would like to reach 100% of cpu usage (I have 700Mhz) without freezing the system. So please don't suggest commands like the fork bomb.

  • 1
    Does this help? – devnull Feb 18 '15 at 19:02
  • I don't have stress installed and I can't run make... – UserK Feb 18 '15 at 19:05
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    Wow actually yes. The guy suggests cat /dev/zero > /dev/null -> 100% of cpu usage. Love this useless command! @ DevNull, your name appears in the command – UserK Feb 18 '15 at 19:08
  • Try cat /dev/zero. – jimmij Feb 18 '15 at 19:10
  • @jimmij with your command I get only 60% – UserK Feb 18 '15 at 19:12

For each core:

dd if=/dev/zero of=/dev/null


while :; do :; done

I suggest looking at this thread for some answers.

One approach like you found is:

cat /dev/zero > /dev/null
cat /dev/random > /dev/null

Compressing video always does it for me, especially since ffmpeg allows you to specify threads.

Something like this (warning, this is an intentional infinite loop):

while [ yes ] ; do ffmpeg -i samplevideo.mp4 -vcodec libtheora -an -b:v 25000 -g 1 -threads 24 -y output.mkv ; done

You could also calculate primes. It starts out simple but in the higher range, it'll get yer CPU churning.


int main(void)                                                               
int i,n,q;                                                                   

for(i=2;i>0;i++) {                                                           

Compile that with gcc:

gcc primes.c -o primes

And run it.

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