CPU buzzing sound

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CPU buzzing sound

CPU buzzing sound can be caused due to various reasons. However if the sound is more during load then the most probable reason is transformer in SMPS which creates magnetic field and even slight movement of magentic material in the field creates sound. Refer to http://superuser.com/questions/19968/processor-noise-what-generates-it for better description.

To look at current temperature use:

1. Run 'sensors-detect' program to detect sensors in the system. This needs to be done only once.
2. Run 'sensors' to see various temperatures.
3. For live monitoring use:

   watch sensors

Steps learned from http://pkill-9.com/monitoring-cpu-and-motherboard-temperatures-in-linux/

Erlang program to generate 100% CPU load

To generate 100% CPU load across all cores following simple erlang program can be used:

-module(a).
-compile(export_all).

start() ->
  Pid_list = lists:map(fun(_) -> spawn(?MODULE, waste_cpu, [0]) end,
lists:seq(1,100)),
  Pid_list.

waste_cpu(N) ->
  waste_cpu(N+1).

To use this following steps can be used:

1. Install erlang using ' yum -y install erlang'
2. Save program in file named a.erl. If different filename is used then module() declaration would have to be changed.
3. Compile program using 'erlc a.erl'
4. Run using

   erl
   a:start().

5. To stop program use 'Ctrl+C' to stop entire erlang shell.

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