According to Apple upgrade specialist Other World Computing, the latest all-in-one design makes it all but impossible to replace the hard drive in the machine with anything but an Apple-fitted device should it fail or need expansion.
At issue is the way Apple measures the hard drive temperature to control cooling fans, as well as the connections used by the company.
Apple upset would-be home upgraders back in 2009 when it changed the way heat sensors worked, meaning that replacing the hard drive with all but a select few models sent the fans into noisy overdrive.
Now the iMac maker has included a proprietary connection that makes the problem even more difficult to work around, with self-installed drives showing error messages in the Apple Hardware Test diagnostics tool.
“For the main 3.5in SATA hard drive bay in the new 2011 machines, Apple has altered the SATA power connector itself from a standard 4-wire power configuration to a 7-wire configuration,” said Michael Perry in a post on the company's blog.
“Hard drive temperature control is regulated by a combination of this cable and Apple proprietary firmware on the hard drive itself," he said.
"We've found that removing this drive from the system, or even from that bay itself, causes the machine’s hard drive fans to spin at maximum speed and replacing the drive with any non-Apple original drive will result in the iMac failing the Apple Hardware Test."
The result, said Other World Computing, was excessive fan noise as the cooling system goes into overdrive. The company said it had tried a variety of work-arounds intended to make an upgrade possible, but had so far failed.
“In short, the Apple-branded main hard drive cannot be moved, removed or replaced,” the company said. “It really begins to raise questions: is this planned obsolescence at work?”
This article originally appeared at pcpro.co.uk
