Summary The Blame view becomes very sluggish and laggy when inspecting large files with extensive commit history. Scrolling and hovering over blame annotations drop frames noticeably. Steps to reproduce Clone the open-source Transmission repository. Open the repository in Sublime Merge. Locate macosx/Controller.mm (a large Objective-C++ file with deep git history). Open the Blame view for this file. Try scrolling rapidly through the file or moving the mouse cursor across the blame gutter...