Comment by int_19h

Which version of VS, and what language? If you're using VS 2010 or earlier, then both C# and VB were running the build (MSBuild and compilers both) on UI thread, so responsiveness was as bad as you'd expect it to be with such architecture. From VS 2012 onwards, VB builds on a background thread, and C# builds out-of-process (which also makes it scale on multi-core systems).