How to slow down clock speed of processor I recently bought a new MacBook Pro which sometimes goes too fast.  I frequently program for Mathematica, and on my old 2007 MacBook Pro I usually got a feeling for inefficient code when it runs sluggishly (that's when I decide "gee, I wrote some garbage code.  Maybe I should spend a couple hours fine-tuning it").  However, on my new Mac, everything just runs zippy fast.  

Is there a switch on the Mac that lets me slow down the CPU to, say, 1 GHz?
If your concern is how efficient your software is, let me suggest a more engineering-oriented solution that will let you keep your MacBook running at full speed:

Use the profiler built into Mathematica.  This will let you identify the parts of your computations that consume the most time without having to resort to seat-of-the-pants measurements that only work on slow hardware.