I find Amdahl's Law very useful for parallelizable work as well. Or at least, I find it trivially scalable to parallel case. Often it helped for me in modeling

I find Amdahl's Law very useful for parallelizable work as well. Or at least, I find it trivially scalable to parallel case. Often it helped for me in modeling how interconnect would be a possibly limiting element for a task even for embarassingly parallel tasks.