Matlab HIGH cpu usage even when idle

The CPU load is very high all the time. Even fresh after starting matlab with no variables and no programs running.

Its about 35%-45% all the time. Here you can see the trace in time of Matlabs cpu load:

Setup: r2012a on win7 64bit, 8gb ram, 200gb free disk space,intel U9400 2core cpu(laptop),java Version 6 Update 31.

What can be causing this?

thx

[per isakson]

Did you ask Technical Support? Matlab shouldn't do that. Something is wrong.

[Germán]

I'm getting the exact same behavior, I'm running R2012a on linux. To make it worse I always leave 2 sessions open which use 100% of of 2 cores when idle.

[Walter Roberson]

Datapoint: I never get this behavior on OS-X Lion with R2012a.

[Germán]

For the sake of people who might be having the same issue I finally solved it. It was the JxBrowser renderer, the issue starts after the first time I open a help window. In order to use the HTML renderer I included

 com.mathworks.mlwidgets.html.HtmlComponentFactory.setDefaultType('HTMLRENDERER');

on my startup.m and that stopped the high cpu usage.

[Walter Roberson]

Thanks for the update.

[Christoph]

There is now an answer from the Mathworks Support team to this very question: http://www.mathworks.com/matlabcentral/answers/114915-why-does-matlab-cause-my-cpu-to-spike-even-when-matlab-is-idle-in-matlab-8-0-r2012b

[ondrej]

HTMLRENDERER does NOT solve it. sad. very sad. octave and R...

[Pief]

2019 and still have this problem. matlab_R2017b using a lot of energy/memory (it's always 'using significant energy' according to the battery dropdown) even when not running any code. macbookpro 2.7ghz, 8gb ram, macos mojave 10.14.2. Any solutions?

[Brett Schmidt]

I am also suffering this issue right now. I can't even use the text editor.