Questions

Question 1: What do I do if my IDE uses a lot of CPU power? System task manager shows constant usage or frequent spikes over 50-100%.

Question 2: What do I do if my IDE is very slow? IDE still can be used but everything feels laggy: editing, scrolling, unfolding menus, etc.

Things to keep in mind

Under normal circumstances, CPU is used while the projects are indexed and when you edit the code (to run inspections, highlighting, etc.). During those periods, CPU usage spikes (even up to a 100%) are normal and not a reason to panic. As long as usage returns to normal after the IDE's heavy-lifting is completed, you are good.

However, if CPU usage is unusually high when the IDE is idle, it could be that something is still running under the hood (or preventing other stuff from running). In such cases, a CPU snapshot can help understand what's going on and fix the problem.

Solutions

First, make sure that:

• IDE default directories, installation folder, process itself (eg. idea64.exe) and project files are all excluded from the ANTIVIRUS / Firewall scan. For more information and instructions, see Antivirus Impact on Build Speed and Slow Startup on Windows. Splash screen appears in more than 20 seconds.
• The IDE is installed on a fast local drive and project files are not located on network drives.
• Unnecessary folders are excluded from indexing (mark them as 'Excluded' in the File | Project Structure | Modules | Sources dialog if you are working on a large project).

Then, try the solutions below:

• Increase the heap size in Help | Change Memory Settings. If it is too low, Garbage Collection process runs too often, using up the CPU and slowing down the IDE. You can increase it up to 85% of overall available memory.
• Temporarily disable all downloaded plugins and restart the IDE: File | Settings (Preferences) | Plugins | ⚙ | Disable all downloaded plugins
• Switch the runtime JDK to default JetBrains Runtime in case something else is selected.

⚠️ What to send to support if nothing helped

If the problem persists, please provide additional data for analysis:

1. IDE logs (entire archive): Help | Collect Logs and Diagnostics Data. We will look for exceptions and check your system environment settings.
2. A CPU snapshot that captures at least 20-30 seconds of IDE performance during high CPU usage: Help | Diagnostic Tools | Start/Stop CPU Usage profiling To keep the readings clean and on point, start the profiling only when performance actually drops, and stop it right after you are done.

All files can be attached to the support request or uploaded privately to our server. Make sure you provide the id of the upload so that we can find it.