At the International Solid-State Circuits Conference in San Francisco this week, Intel revealed details of its new low-power processor, which promises to deliver performance similar to a low-end laptop in a package that uses only a bit more power than a smartphone. The design is innovative–and significant since it marks the start of a new effort by Intel (remember XScale?) to conquer the handheld world. But does the world really want Silverthorne-based Ultra-Mobile PCs (UMPCs) and Mobile Internet Devices (MIDs)?
Silverthorne is hardly a new name. Intel first talked up the chip at the Intel Developer Forum in Beijing last spring. And at CES earlier this year, it showed prototypes of UMPCs and MIDs from 15 different companies all based on Menlow, the new platform that includes both the Silverthorne processor and a chipset named Poulsbo. But this is the first time they’ve discussed the new microarchitecture in detail.
Intel manufactures Silverthorne using 45nm process technology with a high-k dielectric (a high-resistance insulator based on hafnium rather than the usual silicon dioxide) and metal gates. This is the same technology used in the new Penryn desktop and laptop chips. (Since introducing it last November, Intel has already shipped 32 Penryns for desktops, laptops, servers and workstations.) Silverthorne consists of 47 million transistors on a die that measures only 24.2 square millimeters. To put that in perspective, the dual-core Penryn measures 107 square millimeters. You need a small chip to build an ultra-mobile gadget, of course. But it also makes Silverthorne cheaper to manufacture since Intel can fit thousands of chips on a single silicon wafer.
Though it can reach speeds of 2.5GHz, Silverthorne will likely be available at clock speeds between 1.5GHz and 2.0GHz with a TDP ranging from 0.6 to 2 watts. This is peak power, and Intel was quick to point out that the power consumption under more typical usage and during idle time will actually be much lower–measured in “hundreds of milliwatts.” The ultra low voltage versions of the Core 2 Duo, such as the U7700, have a TDP of 10W, but a more accurate comparison is McCaslin, the current platform for UMPCs that uses Intel A100 and A110 chips with a TDP of 3W.
