Apple bans PC SDRAM for users own good

Firmware update blocks non-Apple-specified memory

Updated Apple's scheme to eradicate crashes resulting from dodgy DRAM by blocking the use of non-standard memory through software is unlikely to be reversed - despite the number of users now stuck with useless memory modules.

The Mac maker's plan emerged after it released firmware updates for Macs equipped with PowerPC 74x0 processors - aka G4-class machines - and lesser FireWire-supporting machines.

The updates force the system to ignore all but Apple-specified SDRAM. Apple certifies its machines only to use 3-2-2 SDRAM. However, with superior 2-2-2 SDRAM now prevalent in the x86 world, many users have upgraded their Macs with this version of the memory standard.

So have we, though because we're still getting plenty of mileage out of our Blue'n'white G3, we were unaffected by the firmware updates. However, we've never had a problem with the two 128MB 2-2-2 SDRAM DIMMs we have installed alongside the Apple-installed 128MB 3-2-2 module. MacOS 9.1 works just fine with them all.

In a remarkably 'we know best; it's for your own good' sort of statement, an Apple official has just told MacCentral that Apple has no plans to remove the block the new firmware imposes on certain types of SDRAM.

"The update includes a new check that validates whether the installed memory in the machine is compatible. The check was added to help alleviate random crashes and stability issues. The new memory test disables memory DIMMs that are found to be out of specification and DIMMs that cannot be determined to be compatible. As a result, some third-party memory that was recognised by previous versions of firmware may no longer be recognised after the updates," said the staffer.

And the company won't fix the firmware to allow 'non-standard' SDRAM, because it's bad for you, dear, and mummy would get cross if you put any of that nasty PC SDRAM into your Mac...

Actually, we suspect the motivation to be financial. Mac users are still free to buy suitable SDRAM from any supplier - it's not as if 3-2-2 is a proprietary memory scheme - but it does ensure that Apple's tech support should be plagued with far fewer call-outs due to poor quality RAM.

After touting the ease with which the Power Mac can be upgraded, Apple now seems to be working to reverse that. What next, we wonder? A return to 'opening this case will void your warranty' stickers? ®

Update

Actually, it may not, after all, be a 2-2-2 vs 3-2-2 issue. Several Register readers report that their 2-2-2 DRAM works fine post-update. That suggests that the issue may relate to the way the blocked DIMM is identifying itself to the RAM checker. Apple System Profiler lists one user's DIMM as a 2-2-2 module; in our system, the RAM ID is blank, suggesting it can't tell what type of SDRAM it is.
End of Update

Related Link

MacCentral's SDRAM story

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