If you were wondering how the Zune HD could pack in such iPod touch-beating smoothness into such a small size, we might have an answer for you: It's packing Nvidia's teeny, high-performance Tegra processor.

As we explained in our Giz Explains: Low-Power Chipsets, Nvidia's Tegra proc is designed to handle high-def video and Flash with buttery smoothness in small packages, just like the Zune HD. So while this is as yet still unconfirmed, given that we haven't had confirmation from Microsoft, it makes a lot of sense and would actually be a very smart move—and the sources reporting the rumor seem very certain that it's true. With a Tegra processor, the Zune HD would certainly be able to decode videos with far less necessary power than with any other chipset, which means better battery life combined with better video quality. What else could you want from a next-gen PMP? [PC Perspective]