Some users of new MacBook and MacBook Pro laptops are reporting that their machines become unstable or lock up after they add third-party memory, according to messages posted on Apple Inc.'s support forum.
Users of Apple's newest laptops -- the aluminum-cased models that the company debuted in October -- claim that upgrading with RAM from reputable suppliers leaves their laptops prone to crashes and lockups.
"Mine freezes after about 7 hours, never less," said a user identified as "mmike70" in a message posted to the longest thread on Apple's MacBook support forum that discusses the problem. "It's crashed under all conditions, under load or no load, AC or battery."
Like many others who posted to the same thread, mmike70 said he had ordered more RAM from Other World Computing (OWC), an online retailer that specializes in Mac products.
"I have upgraded my new MacBook with the OWC 4GB package," said "JDTech12308" on the thread. "Since [then] I have experienced a total system freeze about 6 times. I am thinking about putting the original RAM back in."
In most cases, users who did exactly that reported that their MacBooks worked fine from that point on. Others reported stranger behavior while experimenting. "I found that 3GB configuration using one of the original 1GB ram in either slots works fine," said "nikushima" in a long message. "I have exchanged the 2GB RAMs to see if one of them are bad. But both worked fine in the 3GB."
Later in the thread, nikushima reported his conversation with Apple technical support. "They claim that the RAM from OWC lacks memory management, something like non-polarity in the old RAM chips," nikushima said. "So if one of the Apple 1GB RAM is used, it works because it uses the memory management from the 1GB chip."
Although OWC was the most-frequently cited supplier by users, some also noted that they were having trouble with memory bought from Kingston Technology Corp. and Crucial.com, the online arm of chipmaker Micron Technology Inc.
Recent buyers of MacBook Pro laptops have also been reporting problems they say can be traced to third-party RAM. On one heavily-trafficked thread -- it has nearly 6,000 views, a substantial number for Apple's support site -- one user said he had been contacted by an Apple engineer after he had posted several messages, and sent an e-mail to CEO Steve Jobs .
According to William Brocklebank, the engineer said Apple is "very aware" of the problem and that it was due not to non-Apple memory, but because users were bumping up the machines to 4GB.
"They are about to release a software update to address it. He said that officially it might take up to a week or two for this to come out but unofficially we could expect it within a matter of days," Brocklebank wrote on Dec. 4. "In the meantime he said that a solution could be found by removing one of the 2GB sticks and replacing it with the original 1GB."
Apple did not respond to several questions earlier today about the RAM issue, including whether it was looking into the problem and when a fix, if one is applicable, would be released.
Both the aluminum MacBook configurations and the lower-priced MacBook Pro come with 2GB of memory standard; adding another 2GB at the time of purchase bumps up the price by $150. The higher-priced 2.53GHz MacBook Pro packs 4GB.
At Crucial.com, meanwhile, a 4GB kit -- which consists of two 2GB modules -- costs $125.99 plus shipping; OWC charges 94.99 for the same amount of RAM.
This story, "MacBook Users Report Lockups" was originally published by Computerworld.