"There's nothing magic about ARM" is right. Atom, for example, seems competitive as a low-power architecture now that Intel's really trying to get into the mobi

"There's nothing magic about ARM" is right. Atom, for example, seems competitive as a low-power architecture now that Intel's really trying to get into the mobile market. The open question is whether cheap power-focused cores, from any maker, can compete against big server chips, and I think they do have a niche. Low-power server makers probably admit, in their hearts, that the workload their stuff works best with is specialized. CPU-munching apps in scripting languages, or very CPU-intensive data work (full-text searches, say), are not what they're good for. Static content, memcache, and boxes that basically broker between other nodes and do very little 'thinking' themselves are candidates. As some Googlers pointed out, any work where the CPU causes much of the user-visible latency is right out. I'd add that good low-power-CPU servers don't just look like regular servers with a low-power CPU slotted in. You need low-power storage, i.e., Flash. You probably want lots of cores to amortize the energy cost of memory, etc., so that means it works best with a future uarch like Cortex-A15 that supports that. You want low-power memory. Then servers are probably easily sub-1U, so you get a blade-like physical layout, with some resources shared among nodes. Caldexa probably would rather not hear this, but you might have to cut price, not just improve power use and density, to secure ARM a niche against big, fast Intel chips in the DC. I think that can be done over time, because the premium Intel charges on top of chip maufacturing cost is a lot and ARM IP is relatively cheap. But it may make it hard for Caldexa to make back their initial R&D costs unless 1) some early-adopter customers pay a big premium (possible--Facebook, you into this?), 2) the market eats it up with surprising speed and soon everyone's got some ARM nodes in their racks -- seems unlikely, or 3) investors put in enough to outlast a long slow growth period (and I could see an ARM manufacturer like Qualcomm or Nvidia doing that with their own ARM architectures, but that may not help Caldexa or its investors). Any comparison's a stretch, but consider that ARM consumer devices aren't only more mobile than high-end computers, they're cheaper too. I look forward to eating these words in a few years.