compiling suddenly extremely slow

Hi,
I was using Arduino IDE for about two year on this computer and everything was fine. But last week, the compilation started to be very slow. Even complex projects vere usually compiled in few seconds, but now even the blink sketch tooks about 2-4 minutes to compile. IDE is fast, uploading is fast, only compiling tooks long.
I have Windows 10 and when compiling, CPU usage is at 10% and usually I cannot find the compiler process in task manager, but when I do, it usually takes less than 2% of CPU usage.
How to fix it? It war working fine for a long time…

This is often caused by an antivirus program. To determine if that is the cause, TEMPORARILY disable the antivirus for a single compile. Note that the second compile of a sketch if there have been no changes in the Tools menu settings since the last will be faster so be sure to account for that. If disabling the antivirus solves the problem of the slow compile then you will need to whitelist the folders the Arduino IDE uses in the antivirus program. I can help you find those if necessary.

pert: This is often caused by an antivirus program. To determine if that is the cause, TEMPORARILY disable the antivirus for a single compile. Note that the second compile of a sketch if there have been no changes in the Tools menu settings since the last will be faster so be sure to account for that. If disabling the antivirus solves the problem of the slow compile then you will need to whitelist the folders the Arduino IDE uses in the antivirus program. I can help you find those if necessary.

Well, I don't see much difference. Disabling antivirus had no impact on the compile time, no matter if I changed the sketch or not. Compiling Blink still takes few minutes.

@ parmanik

You have 66 posts under your belt and I would have hoped by now you knew what extra information to provide.

All I can gather from your post is that you have windows 10 ! Slow compiles tend to be mainly under windows 10 for the most part and there are a lot of other posts about slow compiles that may give you additional clues as to what to try...

Something that works her on occasion under win 7 x 64 is to delete or rename the arduino15 folder Rename is often better as you can then just copy the preferences file over.

First couple of passes may take a little longer but I have seen it help once all the board cores were back up to date etc.

But PLEASE add more information...

Well, I have Windows 10 x64 on Thinkpad E550, latest version of IDE and latest version of Java (tried reinstalling both), all boards up to date. I wasn't making any changes to my system, just one day it become slow.

Ballscrewbob: Something that works her on occasion under win 7 x 64 is to delete or rename the arduino15 folder Rename is often better as you can then just copy the preferences file over.

Where exactly should be the arduino15 folder located? I tried searching for it, but it returned no results.

That is mentioned all across this section of the forum but its quite often a hidden folder so I will leave it up to you to search around in here so I dont have to do it for you.

Arduino15 folder locations:

You can find the location of your Arduino15 folder at the line following File > Preferences > More preferences can be edited directly in the file.

On Mac OS X: /Users/{username}/Library/Arduino15

On Windows: Arduino IDE 1.6.5r5 and previous: C:\Users{username}\AppData\Roaming\Arduino15 Arduino IDE 1.6.6 and later: C:\Users{username}\AppData\Local\Arduino15

On Linux: /home/{username}/.arduino15 (a.k.a. ~/.arduino15)

If you're running the Arduino IDE in Portable Mode then the folder named portable inside the Arduino IDE installation folder will be used

Ok, so I tried renaming the folder and still I don’t see anychange.

I had the same problem, to fix it I closed the IDE and renamed the preferences.txt file. I restarted arduino and manually entered my changes. It worked, my IDE was fast again, this time I made another copy of my preferences file just in case I come across this problem again.

I was working on my Pic Basic Pro development system because it is a whole lot easier than C++ that Arduino uses. I use the Mecanique IDE.

Where my Arduino UNO compiles a sketch in about 1 minute, the PBP system (An MELabs LabX1 with 16F887 mcu), takes about 5 seconds from compile to program (it's two operations).

The code in both cases do exactly the same thing.

It's not your computer, it's Arduino IDE.

queenidog: Where my Arduino UNO compiles a sketch in about 1 minute, the PBP system (An MELabs LabX1 with 16F887 mcu), takes about 5 seconds from compile to program (it's two operations).

The code in both cases do exactly the same thing.

It's not your computer, it's Arduino IDE.

You're comparing apples to oranges. If you wanted to make a valid conclusion about it being the Arduino IDE, you would need to compile the same code using the same compiler so that the only variable is the use of the Arduino IDE.

It's possible for slowness to be caused your computer and the Arduino IDE. Yes, Arduino IDE 1.6.6 and newer are slow to compile. The reason for this is the improved dependency resolution requires a lot of extra processes to run. However, if, for example, your antivirus is running a scan on each of those processes then you will also have an extra significant slowdown that is not caused by the Arduino IDE.