Each of the 820 million transistors on Intel’s three-gigahertz quad-core processor is only 45 nanometers across, 30 percent smaller than those on previous commercial chips. Smaller transistors need thinner layers of electrical insulation–or dielectrics–which is hard to acheive with the traditional insulator, silicon dioxide. With its 45-nanometer chips, however, Intel has begun using a new insulator, hafnium oxide. The quad-core processor (shown here) will probably be used in network servers; a smaller, dual-core processor could turn up in high-end desktop computers.