Edit: After updating to 3.2, same issue is happening.
Sourcetree has been consistently taking up ~110% of my computer's memory, and I have to keep killing it. Not sure what is causing it. It's almost unusable.
I find that viewing files with a lot of changes slows things down drastically and that those resources are not release, even after that file is no longer being viewed in the UI. Even if that file is staged or otherwise removed from the list, the resources are still taxed. It is resolved by restarting SourceTree, but is a very frustrating issue.
I am running on Windows version 3.2.6 and was looking for a resolution to this and see that there isn't one in the release notes.