ARM faces growing pains

In truth, ARM is gaining market share in low-power embedded applications, but the company still has a long way to go to challenge the reigning microprocessor kings. Also, software compatibility hurts ARM as much as it helps. And, there are many vertical markets which will remain inaccessible to ARM cores just because they are standardized.

Intel in particular has a 20-year head start over ARM, resulting in a maturity, sophistication and veneration that will be hard to displace by a 12-year-old. Intel's ecosystem of support chips, subsystems and software is unparalleled in the industry and addresses many more real-world issues than the low-power and small die size that makes ARM a no-brainer for many new designs. From the mobile space where Atom offers x86 compatibility that even ARM's most sophisticated cores cannot match, to the server space where Intel's Xeon already solves the most vexing issues facing datacenters today, Intel versus ARM remains a brain-teaser. For instance, the fast-growing cloud computing space uses virtualization to offer mobile device users access to applications running on servers for which Intel has a top-to-bottom solution – VTx – which securely links x86-based mobile devices with Xeon-based cloud computers. ARM, on the other hand, is still pursuing virtualization extensions that could offer similar integration of mobile devices into cloud computing realms.

"ARM is becoming more and more mature – its graduated from its initial light-weight processors for mobile devices to beefier processors like the A15 which can compete with Intel's Atom, but they are not yet in the Xeon class" said Sergis Mushell, principal research analyst at Gartner Inc. "The battle has just started – the relay gun has been fired, but the race has just begun."

ARM has recently started penetrating the wireless basestation market with a vengeance, driving a stake in the heart of MIPS Technologies, and landing lucrative new accounts such as for Freescale's popular QorIQ basestation processors.

Interchangable risk
However, standardizing on ARM cores may eventually hurt margins at TI, Freesale, LSI Logic and elsewhere, as they compete for the same sockets since one of ARM's advantages – interchangeable software – will also enable processor vendors to become interchangeable.

"ARM is now threatening the ecosystem of MIPS – going into basestations, going into networking, and gaining mainstream licensees like Texas Instruments, Freescale and LSI," said Mushell. "But all these vendors are going to be competing for the same piece of business, and it will be really easy to replace one vendor's ARM processor for one of the others, which could drive the ASP [average selling price] down significantly."

For many applications, proprietary architectures can actually be an advantage – witness HP's recent decision not to support ARM on Windows 8 tablets. Proprietary cores can also serve specific markets needs that do not fit into ARM's one-size-fit-all philosophy. For instance, Infineon's Tricore, Renesas' VH/RX and Atmel's AVR all serve specific market segments that will not be going away any time soon.

"Though it's true that the ARM ecosystem for embedded microprocessors and microcontrollers is growing at a blistering rate, there are applications – such as in automotive microcontrollers or networking microprocessors, where manufacturers have found it useful to maintain proprietary architectures," said Adib Ghubril, research director, Gartner.

The other dimension that ARM's "no brainer" argument is skirting is heterogeneous multicores. ARM currently has extensions aimed at addressing DSP, vector processing and other specialized needs, but at least for now, chip designers are more likely be use an asymmetric architectures – an ARM core in combination with a non-ARM heterogeneous core – to meet their specific needs.

"And a new war is about to begin – the multicore wars – and here ARM will likely not emerge supremely victorious, because devices are taking on what we refer to as asymmetric architectures to meet requirements specific to end-applications," said Ghubril. "These asymmetric architectures combine heterogeneous cores together such that an ARM may be sitting next to a proprietary DSP."

- R. Colin Johnson
EE Times