If you're one of those who took the leap into a first wave of Intel-based smartphones like the RAZR i, you're likely the sort to wonder exactly what makes them tick. SemiAccurate certainly does: it just posted some previously inaccessible diagrams that help reveal how Medfield's system-on-a-chip heart, Penwell, is mapped out. As a die shot shows, the Atom core is seemingly the least important part of the design -- the PowerVR SGX 540 graphics, camera processing and input-output interfaces dominate the crowded silicon. Between this dense, all-in-one design and stacking up to 2GB of RAM directly on top, Penwell occupies about 17 percent less space than its Moorestown ancestor and helps explain why we're looking at Atom-powered phones instead of another round of MIDs. We wouldn't get too comfortable with the current generation, though, as Intel is gradually warming up 22-nanometer chips that could make Penwell seem old hat.