MacBook Pro: Western Digital hard drives can cause kernel panics due to conflict with sudden motion sensor

MacFixIt reader James Ehrler reports on the discovery and dissection of an issue where the "ShockGuard" mechanism built into Western Digital Scorpio drives conflicts with the MacBook and MacBook Pro anti-shock mechanism (sudden motion sensor), resulting in a kernel panic when certain types of physical movement are applied to the machine.

A posting to the MacSpecialist Web site reads:

(We ordered) a white MacBook configured with a SuperDrive. [...] We picked up the 5400rpm 120gb Western Digital Scorpio from Other World computing. Upon arrival we quickly imaged the stock drive to an external and popped the Scorpio in. [...] We noticed in the first day or two that we were getting a few kernel panics - wrote it off as a weird coincidence and went about our work. Then it happened again, and again and again. After taking out the new memory and replacing it with the stock memory - we were still getting kernal panics. Then we took out the Scorpio and the put the stock drive and shebam the kernal panics stopped. [...] A week went by and we had another new drive in hand. After repeating the install and clone, we waited. It didn't take long, as soon as the computer was set down on the table it had a kernal panic.

"A light bulb then went off... we started to associate the panics with movement. Then it hit us like 3 tons of bowling balls, the Scorpio has built-in shock protection. The ShockGuard technology that WD employs is interfering with the Macs own head parking technology. We placed another call into Other World and returned the second Scorpio in exchange for the slightly more expensive Seagate Momentus (which does not have built-in shock protection). After installing the Momentus and cloning over the now tired image, we haven't had a single kernal panic.

"All that said, if you have a MacBook or MacBook Pro, do not upgrade to the WD Scorpio line of hard drives. They are definitely fine drives, just not fine for MacBook/Pro owners."

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