ECC error reported

Question

Level 2

476 points

ECC error reported

In system profile I have one RAM module show an "ECC Errors". I ran a test with TechTool Pro 5 and it says the memory all passed. Obviously I'm confused. Is the RAM bad or is the error in system profile?

Mac Pro 2x2.8 Quad, 8G ram, Mac OS X (10.6.2), Acer 24 inch, 300, 500,2x 1000 GB drives

Posted on Dec 28, 2009 7:45 AM

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Answer 1

The hatter

Level 9

60,980 points

Dec 28, 2009 8:07 AM in response to James Borzak

Run Apple Hardware Test. Might also run Memtest.

Check your system and files for errors, parity errors can and do result in writing garbage or corrupt information to disk (hard to spot).

And then get the RAM replaced as well.

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Answer 2

James Borzak Author

Level 2

476 points

Dec 28, 2009 11:54 AM in response to The hatter

Restarted computer and it went away. Running full test with TechTool Pro 5 now, its been running for 3.5 hours, probably got a few hours to go.

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Answer 3

The hatter

Level 9

60,980 points

Dec 28, 2009 1:15 PM in response to James Borzak

ECC errors don't go away, they may not be reported, and the system doesn't register those errors between boots.

Memtest can be run concurrently to test small chunks, so 256MB in 20 Terminal windows. Very effective.

And of course there tend to be better stress tests in Windows or booting from Memtest CD.

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Answer 4

James Borzak Author

Level 2

476 points

Dec 28, 2009 2:32 PM in response to The hatter

So although it appears ok now, the chip set is most likely failing? It has a life time warranty

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Answer 5

The hatter

Level 9

60,980 points

Dec 28, 2009 3:02 PM in response to James Borzak

Lifetime warranties 'vary' vendor to vendor to some degree.

It is the potential data corruption I pointed to earlier that is most expensive sometimes. Disk Warrior and TechTool Pro should be able to spot errors, but I had to 'start over' due to too many extension conflicts and each rerun of DW would report it had to repair something. Lesson: don't run on ECC memory triggering parity errors.

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