Most Linux and Windows apps do any significant computation except when relying on (usually) native/C/C++ libraries that do it (GUI, science stuff, IO ...). So i

Most Linux and Windows apps do any significant computation except when relying on (usually) native/C/C++ libraries that do it (GUI, science stuff, IO ...). So it does not really matter if it is coded in Python, C# or C++, as most of the CPU time is spent on native code anyway. Code quality is a way more important factor in app perceived slowness.