Speeding up the Unreal editor by… not using unnecessarily secure hash methods

One good trick when trying to look for ways to optimize software is to stay away from areas that are very likely already quite well optimized, and instead focus on areas that might have been overlooked, either because they are too obscure or don’t show up during regular profiling sessions. This tactic worked well in the past, as shown with my optimization of tooltip creation, or the loading of editor localization files. This was also the reason why I mostly skip over any functions that contain words like “Shader Compilation” or “Shader Source” when I stumble over them in my profiler. The compilation of shaders is a famously long and elaborate process, and I’m pretty sure that very smart people at Epic already spent a lot of time optimizing those areas. That’s the reason why I would, for example, skip the function “Compile Global Shader Map,” even though its runtime would typically multiple seconds: This was, at least, true until one day I skipped over it using an unusually high zoom…