IDE causes high cpu / fan usage

Whenever I ran 1.6.5-r5, the cpu usage skyrocketed and the cooling fan ran at high speed. Adding the Sparkfun FTDI seemed to make things worse.

I recently upgraded to 1.6.12 and have the same behavior. Red arrows on the screenshot shows when the IDE was closed (FTDI not attached).

Windows 7 Home Premium 64-bit, 2.5 GHz i5 CPU, 6 GB RAM laptop.

Haven't found anything via Google re this problem.

Other than using the on-line IDE, is this fixable?

Navigate to the Processes tab. Sort by CPU.

What is first?

What is second?

The first is javaw.exe *32, and the second varies...taskmgr,firefox...

Odd. Here the IDE never goes idle but it also never goes above about 2%; usually staying below 1%.

How does Physical Memory Usage look? About in the middle?

Thanks. Yup, physical memory is about in the middle.

Your computer is not much different than mine (Win 7 Pro, 64b, i7 @ 2.2 GHz, 8 GiB, laptop).

In Device Manager, how many serial ports are listed?

Two COM/LPT ports.

The only ideas I have (all shots in the dark)...

Use Performance Monitor to determine if the CPU is wasting time in the kernel or in the application. If it is kernel time you may have failing hardware or a buggy kernel driver.

--OR--

Run the IDE under a debugger to determine what it is doing.

--OR--

Check the Java version (I don't know how to do that).

Hmmmmmmm... ok, thank you. Will try to figure out how to do those things.

If you don't mind one more thing... if you go to Control Panel and view by small icons, click on Java, and then General tab -> About..., what do you see? I have Version 7 Update 9 build 1.7.0_09-b05

Better than the std process viewer is process explorer from MS HERE

It will show things you would not normally see.

Other reports concerning high CPU usage and Arduinos range from serial modems, bluetooth devices, Antivirus issues, other security software, Actual virus or malware, Other USB devices taking COM resources.

Thank you - I'll try turning off the antivirus, for starters.

All four processors are pegged at 100% after updating Java to the latest version and turning off anti-virus, so those two items are off the list.

Anything here look unusual?

Open a command shell. Run this...

set JAVA_HOME

will do when I get home from work...

JAVA_HOME was not set. I set it (and updated PATH) to point to the JRE.

CPU usage seems better, but it is still far above your 2%.

I (temporarily) set javaw.exe to run on one core, to be sure I was seeing the IDE, and took the following screenshot. Usage hits 100% when compiling (horizontal red line). Before and after, when I'm doing nothing with the IDE, it cycles as shown. Drops to nothing when the IDE is closed (vertical red line). Running on all cores...70-50% during compile.

I googled java high cpu usage windows 7 but found nothing definitive.

One good thing has come out of this: cleaning the fan ports helped reduce fan noise...

Other than the time sponges in reply #7 I am out of ideas.

Ok, thanks - I appreciate all the suggestions. +1

Well, there is one more thing...

Repeat this but click Show processes from all users...
http://forum.arduino.cc/index.php?topic=447871.msg3081763#msg3081763

Make certain Java*32 really is the culprit.

I should have had you do that the first time.

Yes, with "all users," javaw... is still at the top of the heap when the IDE is "just sitting there" (no editing, no compiling, no Boards Manager activity, no serial monitor, etc.) During a compile, a few others briefly reach the top: arduino-builder, ld, extensa..., but javaw is at the top most of the time.

I have just updated to 1.8.1 and I have the same problem. I think it used to happen sometimes, but today it’s all the time. As soon as I start the IDE it goes to 42% CPU forever (both cores). Even without any compile or upload, just leave the IDE sitting there. Stop the IDE and immediately down to 2%. I’ve been around this several times, completely sure it’s the IDE doing it. If I go in device manager and disable ‘Bluetooth RFCOMM’ and COM1, restart IDE, the CPU is only 18%. I’d disable all the COM ports, but I need 1 for the Arduino.

I’ve seen a comment somewhere that there’s ‘port discovery’ and that was/is the problem. I’ve looked through all the preferences to see if there’s anything that I can turn off, not found anything.

It’s really annoying having the fan on full all the time, never mind the power consumption. I hope someone has a workaround or even a full fix.