> Can I ask why that is, and if there is a way to take advantage > of all 4 within python?
Sure. All major programming languages handle concurrency in one of two ways: multithreading or parallel processes. In the standard python interpreter, there is the Global Interpreter Lock (GIL for short) that only allows one thread to run at once. So your option for python are limited to running multiple processes or using a different interpreter. What you are testing, however, is not easily parallizable since the slow concat in particular is very dependent on sequential results. If you want test the quad cores you'll have to run the test multiple times with many different threads to truly stress them. -- http://mail.python.org/mailman/listinfo/python-list
