Apple's possible move from Intel x86 chips to ARM processors for its MacBooks is feasible, but not practical over the next few years because of technical and performance issues, analysts said this week.
In the short term, ARM processors won't be able to deliver the performance MacBooks draw from x86 chips, these analysts said. Apple currently uses ARM processors for the iPhone and iPad, and more power-hungry Intel chips on its Mac computers.
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"It's possible that Apple is looking at ARM, particularly for specialty devices like MacBook Air where thin and light is critical," said Jack Gold, principal analyst at J. Gold Associates. "But as a mainstream chip to power all the Macs, I'd be surprised if they went that route."
Media reports last week suggested that Apple would move MacBooks from x86 to ARM processors over the next few years.
Analysts, however, said x86 processors will continue to remain a staple for Macs, while a move to ARM could increase the support and validation cost for hardware and software.
Moving from Intel to ARM would be a "big risk for relatively little gain," said Real World Technologies analyst David Kanter in a study published this week on the company's website.
"ARM microprocessors are designed for lower performance and unlikely to match x86 performance in the next few years," Kanter said. He also noted some technical issues that may prevent Apple from moving to ARM on Mac laptops. Specifically, Apple introduced this year new MacBooks with the high-speed Thunderbolt interconnect, which was designed with Intel. The interconnect is not yet available for ARM, and Intel may have little motivation to make it available for a rival architecture.
ARM currently has virtually no presence in the PC market. ARM processors are used in netbook-like devices called smartbooks, which have not sold well.
An IDC analyst however predicted last week that ARM would capture a 13 percent share of the PC microprocessor market by 2015, as a result of Microsoft's decision to make Windows available on ARM processors.
Intel chips based on the x86 architecture implement complex instruction sets and wide cache for performance, while ARM focuses more on power consumption and has little experience with complex instruction sets, Kanter said
"Emulating x86 on ARM is eminently feasible, but there is a performance tax. An ARM microprocessor would need to run faster and more efficiently than current and future x86 designs to avoid losing performance and power efficiency for generic software," Kanter said.
Even if Apple decides to move to ARM on MacBooks, it will have to continue using x86 on its high-end Mac Pro desktops, which are based on Intel's Xeon server chips. That could split the Mac product line, and increase the cost required to support different hardware and software.
Replacing Xeons would be pretty difficult, Gold said. ARM processors are not designed to run high-end applications on Mac desktops.
With laptops and desktops running on different chips, maintaining a full OS for two different architectures could be a nightmare, just as Microsoft may find as it ports the upcoming Windows 8 to ARM, Gold said.