Many people know ReSharper as a huge hog on system resources – an they are, to some extent, right. It gets especially frustrating when it starts slowing down typing. I like to do followin test of Visual Studio performance: open one of your larger and more complicated source files, put the caret to the first line and then hold down the down arrow key. It should blaze through the file rapidly, and more importantly at a very consistent pace. If it lags a bit here and there, you are having performance issues that are sure to impede your coding experience.
I have been dealing with this input lag for months and was sure that ReSharper was the cause (disabling the extension would fix the issue). I, however, find ReSharper indispensable for my work, so I kept dealing with it. Little did I know that there is a very easy way to improve performance significantly: disable nullability analysis. To do this, go to ReSharper → Options → Code Inspection → Settings → Value analysis mode → select Disable nullability analysis.
While nullability analysis is theoretically nice, I have always found it more annoying than useful. While ReSharper provides annotations for much of .Net framewor, it doesn’t help at all with 3rd (or 1st) party code.
If your performance is not satisfactory even after disabling nullability analysis, you can go through the ReSharper performance checklist.