Intel's low-power Atom processor (codenamed Silverthorne) launched today in a frequency range from the 800MHz Z500 ($45) to the 1.86GHz Z540 ($160). Processor prices also include the cost of the Poulsbo chipset, and together, these two chips form the basis of the mobile Menlow platform. Details on the chips are shown below—all Silverthorne/Atom processors currently available have 512K of onboard L2 cache.

Silverthorne was designed to be power efficient above all else, and it shows in the core's low TDP rates. TDP on the Z500 is 0.65W, the Z510, 520, and 530 share a TDP of 2W, and the Z540 draws a maximum of 2.4W. These numbers, however, are much higher than what Intel expects the CPUs to draw under standard usage. Average power for the Z500 is 160mW, with an idle power of just 80mW. The only other x86 processor on the market that even approaches Silverthorne's TDP is AMD's Geode LX family, and the Geode, at heart, is a glorified 486 processor.

Clock speed MHz FSB speed MHz SMT Avg power Idle power TDP Price Atom Z500 800 400 No 160 mW 80 mW 0.65W $45 Atom Z510 1100 400 No 220mW 100mW 2W $45 Atom Z520 1333 533 Yes 220mW 100mW 2W $65 Atom Z530 1600 533 Yes 220mW 100mW 2W $95 Atom Z540 1860 533 Yes 220mW 100mW 2.4W $160

As for Poulsbo, it's designed as an integrated northbridge-southbridge and supports a number of features normally found on a standard desktop, including an ATA-100 interface, multiple USB ports, two PCIe x1 channels, and integrated audio and video capabilities. Poulsbo supports a single DDR-2 channel at 400MHz or 533MHz. The mobile Internet device (MID) products that Menlow is intended for are meant to offer users audio, video, and Internet experiences that more closely approach what one would see on a laptop as opposed to a smartphone. To that end, Intel has integrated both an HD audio system and a graphics card it says is capable of offloading the entire HD video decoding process.

Atom never was a smartphone chip

Both Tech Report and Anandtech have really long, slide-filled articles on Atom, and our own Jon Stokes is working on more detailed coverage of both Atom and Nehalem. But if you want a general, one-page lowdown on the Silverthorne architecture and its prospects then you should read Jon's coverage of the Silverthorne unveiling at the recent International Solid State Circuits Conference.

In a nutshell, Atom isn't even close in terms of performance/watt to ARM's Cortex line, and as a platform, even the more highly integrated Moorestown revision that will come out next year won't put Intel into smartphone territory. No, Silverthorne and its immediate successor are aimed at larger form factors than the smartphone, and in that respect they're only Intel's first, slightly awkward steps into embedded territory.

Where Atom and its immediate derivatives will shine is in the Eee PC and OLPC form factors, as well as in very low-cost desktops. Intel claims that Atom offers slightly better performance than the Dothan flavor of the Pentium M (we'll have to see that for ourselves to believe it; and if it's true, it's true only for specific workloads), so it will be a good fit for these two device categories. But as a true embedded RISC competitor, Intel still has a long way to go.

Jon Stokes contributed to this report.

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