We already looked at the various power ratings for the mobile flavor of Atom, code-named Silverthorne, in our article on Intel's new processors. However, Intel also has Atom chips code-named Diamondville up its sleeve for desktops and low-cost laptops. That raises the question: just how much power can one expect a small-form-factor, Diamondville-based desktop to pull?
The guys at VR-Zone have provided an answer the good, old-fashioned way—by hooking a power meter to an actual Diamondville system and checking power draw at the wall socket. The system in question was based on an engineering sample of Intel's "Little Falls" Mini-ITX platform, and it reportedly included a 1.6GHz Diamondville chip, an OCZ memory module, an 80GB 7200RPM hard drive, a Serial ATA DVD burner, and a Fortron Everest power supply.
While running two instances of SuperPI to fully load up the processor (remember that Atom supports simultaneous multi-threading), VR-Zone registered about 39W on its power meter. Assuming 80% efficiency for the power supply, VR-Zone says that works out to only 32W of power draw at full load for the entire system. To put things in perspective, many of Intel's mobile Core 2 Duos have 35W thermal envelopes, so having a full desktop system draw less is an impressive feat indeed.
You can check out VR-Zone's testing in detail in this YouTube video.