I have read that most software today is not written to take advantage of multi-core CPU's (i.e. is not vector based or does not have independent modules). Therefore, a program running on a single core CPU at a higher clock speed may be faster than running it on a dual core CPU at a lower clock speed even though the theoretical throughput of the dual core CPU is higher. This makes sense to me. My question is will CPU intensive tasks (like rendering a DVD) occupy one core on a dual core CPU leaving the other core available to do something else? Or since both cores share the same bus for I/O will the I/0 create the bottleneck? Given the state of software now is the multi-core CPU really worth the extra expense? Thanks in advance for your thoughts.