I have just run code inspections on a project using rather strict settings, getting about 10000 warnings (some of which might be turned off later). Navigating through the resulting tree using ctrl-alt-up/down or the feels really slow – in reality it usually takes somewhat less than a second to move to the next or previous item, but this still feels very very slow compared to everything else. In particular, navigating to the same locations by clicking the same nodes in the same result tree is almost instantaneous! I'm uploading two CPU snapshots which I hope might help you find whatever the cause may be. The first one covers going through a number of warnings (maybe 50-80 warnings) using ctrl-alt-down, letting the result tree expand as necessary. The second one covers going through part of the same list of warnings backwards using ctrl-alt-up; this time the result tree is already expanded and the files are presumably already in memory. Tell me if there's anything else you need to know or any other tests I should do!