The process of converting .NET assemblies into C++ files has historically been single threaded. The il2cpp.exe utility performs this task.. You may have noticed the il2cpp.exe process churning along using a single core. In the fall of 2019 we began a journey to make il2cpp.exe take advantage of all the cores your machine has available. Over the last year we have steadily shifted il2cpp.exe toward becoming a multi-threaded application. Starting in 2020.2.0b2 the process of converting .NET assemblies into C++ files is multi-threaded. For 6-8 core machines the conversion process will see roughly a 60-65% decrease in conversion time. On a 64 core machine conversion time decreased by 73%. It is hard to generalize exactly what improvement you will see in the overall il2cpp player build times. There are many variables that contribute to the total player build time such as C++ compiler settings, your CPU, and more. Broadly speaking here is what you can expect to see Clean player builds will have the least perceived improvement. This is because compiling C++ files dominates the total time. Incremental player builds will see the most perceived benefit because there are fewer C++ files to compile.