Why is IntelliJ 13 IDEA so slow after upgrading from version 12?

Question

While using IntelliJ 13 ultimate edition for a week, it just seems really slow.

First of all, the whole IDE stops for a second or so every once in a while. The Java editor's auto complete is really slow compared to 12 version.

I have not changed anything from the default settings other than using a Dracula theme.

It seems that this is not a problem of my own. Many people suggested setting the heap size higher than default, or clearing the cache, but I have not checked or tested on these suggestion. Do I need to change some setting to improve the new version's performance?

user_1650656 · Answer

Editing the idea.vmoptions file is only a temporary solution until the next product update. See the JetBrains help pages for a more permanent solution to setting these values via the vm settings - https://www.jetbrains.com/help/idea/tuning-the-ide.html

user_1014230 · Answer

Increase heap size for the compiler. By default the value is 700m which is a way too small with increasing number of plugins.

At v2019.1 it located here:

Settings -> Build, Execution, Deployment -> Compiler -> Build process heap size (Mbytes)

After I put 4000 there it solved most my performance issues.

user_7003331 · Answer

My particular case: I had a number of method breakpoints while I was running my code in debug mode, which made my intelliJ slow.

Why is IntelliJ 13 IDEA so slow after upgrading from version 12?

20 Answers