Is there some way of turning-off automatic SonarLint analysis in Intellij IDEA?
I have some 10,000 to 20,000 lines-of-code classes (don't ask, not my fault, trying to refactor). Every time I edit even a single character in the class, the SonarLint plugin makes IDEA unusable for a few minutes.
It is not possible to save the "Automatically trigger analysis" checkbox in the unchecked state in Other Settings > SonarLint General Settings. Is there some other solution to my problem? I really want to use the plugin. I just can't use it in automatic mode.

There was a bug in SonarLint for IntelliJ that prevented the configuration to be properly saved.
It was fixed in the latest version 2.3.2: https://jira.sonarsource.com/browse/SLI-106
About the performance, please make sure you are using the Java analyzer 4.2, as you might be experiencing this problem: https://jira.sonarsource.com/browse/SLI-100.
It is embedded in the latest SonarLint, but if you use the connected mode, you also need to check which version of the Java analyzer is installed in the SonarQube server.
We are always trying to improve performance, so feel free to open a topic in the SonarLint Google group with the verbose analysis log so that we can investigate why it takes so long to analyze the file.