I have a brand new MacBook Pro Retina (8GB, 256GB SSD), which has experienced some issues for past few weeks.

I decided to run memtest after a complete OS X reinstall.

Here's the log :

Copyright (C) 2004-2008 Tony Scaminaci (Macintosh port)
Licensed under the GNU General Public License version 2 only

NOTE: No command-line arguments have been specified
Using defaults: Test all available memory, one test pass, no logfile

Mac OS X 10.9.4 (13E28) running in multiuser mode
Memory Page Size: 4096
System has 4 Intel core(s) with SSE
Requested memory: 5943MB (6232047616 bytes)
Available memory: 5943MB (6232047616 bytes)
Allocated memory: 5943MB (6232047616 bytes) at local address 0x0000000101000000
Attempting memory lock... locked successfully
Partitioning memory into 2 comparison buffers...
Buffer A: 2971MB (3116023808 bytes) starts at local address 0x0000000101000000
Buffer B: 2971MB (3116023808 bytes) starts at local address 0x00000001babac000

Running 1 test sequence... (CTRL-C to quit)

Test sequence 1 of 1:

Running tests on full 5943MB region...
  Stuck Address       : ok              
  Linear PRN          : ok              
Running comparison tests using 2971MB buffers...
  Random Value        : ok 
  Compare XOR         : ok 
  Compare SUB         : ok 
  Compare MUL         : ok 
  Compare DIV         : ok 
  Compare OR          : ok 
  Compare AND         : ok 
  Sequential Increment: ok 
  Solid Bits          : ok              
  Block Sequential    : ok                 
  Checkerboard        : testing 19 of 64

FAILURE! Data mismatch at local BUFA address 0x00000001a144b978, BUFB address 0x000000025aff7978
BUFA Data: 0xaaaaaaaaaaaaaaae, BUFB Data: 0xaaaaaaaaaaaaaaaa

  Bit Spread          : testing   1 of 128

FAILURE! Data mismatch at local BUFA address 0x00000001a42e09f8, BUFB address 0x000000025de8c9f8
BUFA Data: 0xfffffffffffffffe, BUFB Data: 0xfffffffffffffffa

  Bit Flip            : testing   3 of 512

FAILURE! Data mismatch at local BUFA address 0x00000001a0d4f978, BUFB address 0x000000025a8fb978
BUFA Data: 0x0000000000000005, BUFB Data: 0x0000000000000001

  Walking Ones        : testing   3 of 128

FAILURE! Data mismatch at local BUFA address 0x00000001a18c1978, BUFB address 0x000000025b46d978
BUFA Data: 0xffffffffffffffff, BUFB Data: 0xfffffffffffffffb

  Walking Zeroes      : testing   4 of 128

FAILURE! Data mismatch at local BUFA address 0x00000001a21bd978, BUFB address 0x000000025bd69978
BUFA Data: 0x000000000000000c, BUFB Data: 0x0000000000000008

*** Memory Test Failed ***  Please check transcript for details.
Execution time: 512 seconds.

The guys at the Apple Store are sure there is no problem with the RAM.

So why Memtest is failing ? Is it normal ?

  • 2
    I would say, go back to them and show them your memtest. – Matthieu Riegler Oct 21 '14 at 13:53
  • I would, but they say memtest results are not relevant, because it's not Apple certified. – enguerranws Oct 21 '14 at 17:26
  • What does the Apple Hardware test says ? – Matthieu Riegler Oct 21 '14 at 21:49
  • Before the complete MacOs reinstall, it said that one memory module could be defective. After the reinstall, it says there no issue. – enguerranws Oct 22 '14 at 4:14
  • Well, now, it says again that a memory module could be defective. I went back to the Apple Store this morning : Memtest is not relevant, and Apple Hardware test neither. What can I do ? – enguerranws Oct 22 '14 at 8:16

As you said in the comments :

  • Memtest is failing
  • Apple Hardware Test indicates a possible memory failure

This a clearly a bad indicator for your memory.

The fact that a premium reseller is not taking your MacBook Pro for some obscure reasons would make me call a huge bulls**t.

They have to take if it's defective !

  • I can only agree with you, but what can I do ? Go to the nearest Apple Store (but I'm not sure they will do something), or harass my Premium Reseller ? – enguerranws Oct 22 '14 at 9:29
  • Actually, when they run their tests (the guy at the store show me, it takes 10 sec to make it), it shows nothing. – enguerranws Oct 22 '14 at 9:30
  • 10 secondes for a memory that basically no test. Overclocking-addict make memory tests of multiple hours to ensure their system is rock-stable. – Matthieu Riegler Oct 22 '14 at 12:07
  • That's what I said to the "tech guy". But well, no success :) – enguerranws Oct 22 '14 at 12:44
  • 1
    Finally, your answer was the good one : I went to the Apple Store Nantes, the Genius saw my memtest and took it back for repair. 2 hours later, it was done :) – enguerranws Nov 3 '14 at 9:47

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