The claims came on Friday from Japanese site Macotakara. Citing an anonymous source, it reported that Apple, in its internal labs, made "test equipment" of a new Thunderbolt-equipped MacBook Air powered by an A5 processor.
"According to this source who saw live A5 MacBook Air actually, this test machine performed better than expected," the translation reads.
The report also noted it was "not clear" whether this system was running Apple's lightweight iOS operating system, found on the iPhone and iPad, or the full-fledged Mac OS X operating system. It also mentioned that a switch to a processor based on the ARM architecture would require developers to modify their existing applications.
Given the challenges that would come with a transition from Intel processors to an ARM-based CPU, the A5-powered MacBook Air was characterized as an "experiment." The hardware is said to have been built by Quanta Computer.
The latest rumor comes weeks after a separate report claimed that Apple is looking to transition its laptops to ARM processors "as soon as possible." That report claimed that Apple could switch to ARM processors for its laptops when 64-bit variations are available at the end of 2012 or by early 2013.
As the role of ARM CPUs for Apple has grown with the iPhone and iPad, Microsoft also has plans for the ARM architecture in the future, as mobile devices offer longer battery life with the low-power chips. The Redmond, Wash., software giant revealed at this year's Consumer Electronics Show that the next version of its desktop operating system, Windows 8, will also run on ARM architecture.
Last December, Macotakara correctly reported that Apple's second-generation iPad would have a smaller bezel, a flat back panel, and a larger speaker. The site also revealed that Apple was planning an event to announced the iPad 2 in March.
The same site also joined a chorus of others in reporting that Apple will ship its fifth-generation iPhone later than usual this year. A report in March said that Apple was not yet ordering components for its fifth-generation iPhone, and that the anticipated device was not expected to contribute to Apple's fiscal 2011 bottom line. Apple's fiscal year 2011 concludes on Sept. 24, which would put a new iPhone launch in late September at the earliest.