Intel has attracted the ire of Linux enthusiasts by reminding developers that its latest 'Clover Trail' Atom microprocessors won't support the open source operating system.
In a report from the Intel Developer's Forum (IDF) in San Francisco, company presentations described the tablet-oriented Atom system on a chip as "a Windows 8 chip" and that "the chip cannot run Linux."
Although an x86-compatible design the dual-core Clover Trail was always intended to compete in the market for Windows tablets in parallel with Medfield, a single core design meant for smartphones.
None of this is new nor particularly surprising; any x86 design should be able to run Linux but the chip giant has included additional power management interfaces necessary for such devices and not currently supported by the Linux kernel.
Intel's official explanation was an unhelpfully evasive "there's a lot of software work that has to go into a chip to support it in an operating system," which is another way of saying that system on a chip designs don't work out of the box as would have been the case with chip-only designs in standard PCs.
Open source luminary Bruce Perens isn't convinced that Intel is unenthusiastic about Linux for purely technical reasons, however - the Wintel alliance might be in evidence again.
"The details of Clover Trail's power management won't be disclosed to Linux developers. Power management isn't magic, though - there is no great secret about shutting down hardware that isn't being used," he said in a blog. That support would likely arrive on later chips, he predicted.
But more to the point, why would Linux developers want to run the OS on a system that underlines how far Intel still has to go to catch up with power efficiency specialist ARM?
"Why has Atom lagged so far behind ARM? Simply because ARM requires fewer transistors to do the same job," said Perens.
ARM adds some complexity by supporting three additional instruction sets on some CPUs: Two 16-bit versions of their 32-bit instructions, and additional instructions that are optimized for running a Java virtual machine. Even with this added complexity, ARM provides several times the power efficiency of Atom."
In other words, the RISC v CISC battle that Intel won in the 1990s when it saw off rivals to its desktop market has become a disadvantage in the age of mobile devices. Intel's CISC x86 won that war but is now mired in a much longer campaign it is losing.
According to Perens, the Clover Trail is just the latest instalment and it is heading nowhere important.