Did my Mac really fail this memory test? (Memtest 4.22)

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Level 1

60 points

Did my Mac really fail this memory test? (Memtest 4.22)

I recently bought 16 GB memory (at 1600 MHz) for my 15-inch MacBook Pro (late 2011), and ran the Memtest on it.

Apparently, it failed, but take a look for yourself:

mac:~ User$ memtest all 2

Memtest version 4.22 (64-bit)
Copyright (C) 2004 Charles Cazabon
Copyright (C) 2004-2008 Tony Scaminaci (Macintosh port)
Licensed under the GNU General Public License version 2 only


Mac OS X 10.7.5 (11G63) running in multiuser mode
Memory Page Size: 4096
System has 8 Intel core(s) with SSE
Requested memory: 6356MB (6664851456 bytes)
Available memory: 6356MB (6664851456 bytes)
Allocated memory: 6356MB (6664851456 bytes) at local address 0x0000000101000000
Attempting memory lock... locked successfully
Partitioning memory into 2 comparison buffers...
Buffer A: 3178MB (3332425728 bytes) starts at local address 0x0000000101000000
Buffer B: 3178MB (3332425728 bytes) starts at local address 0x00000001c7a0c800


Running 2 test sequences... (CTRL-C to quit)


Test sequence 1 of 2:


Running tests on full 6356MB region...
  Stuck Address       : ok              
  Linear PRN          : ok              
Running comparison tests using 3178MB 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    : testing 181 of 256


FAILURE! Data mismatch at local BUFA address 0x0000000103efe398, BUFB address 0x00000001ca90ab98
BUFA Data: 0xb4b4b4b4b4b4b4b4, BUFB Data: 0xb4b4b4b4b6b4b4b4


  Checkerboard        : ok              
  Bit Spread          : ok                
  Bit Flip            : ok                
  Walking Ones        : ok                
  Walking Zeroes      : ok                


Test sequence 2 of 2:


Running tests on full 6356MB region...
  Stuck Address       : ok              
  Linear PRN          : ok              
Running comparison tests using 3178MB 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        : ok              
  Bit Spread          : ok                
  Bit Flip            : ok                
  Walking Ones        : ok                
  Walking Zeroes      : testing  20 of 128


FAILURE! Data mismatch at local BUFA address 0x000000016ad74688, BUFB address 0x0000000231780e88
BUFA Data: 0x0000000000080000, BUFB Data: 0x0000000000080008 

*** Memory Test Failed ***  Please check transcript for details.
Execution time: 3189 seconds.

Should I return the memory?

I ran this Terminal command with a few other programs open.

MacBook Pro, Mac OS X (10.7.5)

Posted on Mar 21, 2013 8:41 AM

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Answer 1

OGELTHORPE

Level 9

57,329 points

Mar 21, 2013 9:09 AM in response to Rudolfensis

The correct RAM specifications for a late 2011 MBP are: 204-pin PC-10600 (1333 MHz) DDR3 SO-DIMM. 1600 MHz RAM is not compatible and I suggest that you return it and get the RAM with the proper specifications.

The two best sources for Mac compatible RAM are OWC and Crucial.

Ciao.

Your MBP will support 16 GB. That is what I installed in my late 2011 MBP.

Message was edited by: OGELTHORPE

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Answer 2

Rudolfensis Author

Level 1

60 points

Mar 21, 2013 9:19 AM in response to OGELTHORPE

What did you think about the results of the Memtest?

And, nope, I don't think this is the issue:

OGELTHORPE wrote:

The correct RAM specifications for a late 2011 MBP are: 204-pin PC-10600 (1333 MHz) DDR3 SO-DIMM. 1600 MHz RAM is not compatible and I suggest that you return it and get the RAM with the proper specifications.

It is compatible with my chipset: http://ark.intel.com/products/53474/Intel-Core-i7-2760QM-Processor-6M-Cache-up-t o-3_50-GHz

Max Memory Size (dependent on memory type)	32 GB
Memory Types	DDR3-1066/1333/1600

Many other users report it working: http://www.google.com/search?client=safari&rls=en&q=1600mhz+on+late+2011+macbook +pro&ie=UTF-8&oe=UTF-8

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Answer 3

John Galt

Level 10

155,822 points

Mar 21, 2013 9:31 AM in response to Rudolfensis

Rudolfensis wrote:

And, nope, I don't think this is the issue:

It really doesn't matter what you think Rudolfensis. Your 15-inch MacBook Pro (late 2011) requires 204-pin PC-10600 (1333 MHz) DDR3 as OGELTHORPE wrote. Anything else is incorrect.

Many other users reporting it working does not change a thing. Mac memory is either correct or incorrect. Incorrect memory may work, or it may not, but that does not change the fact that it is incorrect. Memtest revealed this for you so consider yourself fortunate for discovering it now, rather than long after its purchase has been forgotten.

Return yours and purchase memory from either OWC or Crucial. There are many complaints regarding incompatible memory supplied by other vendors, even though its specifications are allegedly correct.

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Answer 4

Rudolfensis Author

Level 1

60 points

Mar 21, 2013 9:45 AM in response to John Galt

What are you basing that on? Source?

It is not just what I think, but it is according to Intel: http://ark.intel.com/products/53474/Intel-Core-i7-2760QM-Processor-6M-Cache-up-t o-3_50-GHz

It is clearly stated that my MacBook Pro's motherboard supports 1600 MHz.

What are you basing your position on?

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Answer 5

Mar 21, 2013 9:55 AM in response to Rudolfensis

Intel says the processor will be able to run 1066/1333/1600 MHz memory which is true. But you have to remember - that processor is soldered to a logicboard/motherboard set to run at 1333MHz.

You can't rely on the processor spec - you have to consider the board it's connected in to. It doesn't say it Macbook Pro's motherboard supports it. It says the Processor supports it.

I have done the following in my Macbooks:

Late 2008 Macbook Uni - installed 1333MHz RAM, after a couple of months - keyboard failed - almost bought a new keyboard - decided to install original spec RAM before I take it in for service - keyboard starts working - installed the 1333MHz RAM - Keyboard is dead.

Late 2011 Macbook Pro - installed G.Skill MAC specific 1600MHz RAM - Crashes a few times a day. Installed 16GB Patriot Mac Series 1333MHz - Not one issue since.

You may sometimes be lucky using overspec RAM - it will not however, guarantee that it will work in the long run - if you think that it' works for you with no issues - then go ahead and use it.

Good luck

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Answer 6

Rudolfensis Author

Level 1

60 points

Mar 21, 2013 9:57 AM in response to Bimmer 7 Series

Bimmer 7 Series wrote:

Intel says the processor will be able to run 1066/1333/1600 MHz memory which is true. But you have to remember - that processor is soldered to a logicboard/motherboard set to run at 1333MHz.

You can't rely on the processor spec - you have to consider the board it's connected in to. It doesn't say it Macbook Pro's motherboard supports it. It says the Processor supports it.

I have done the following in my Macbooks:

Late 2008 Macbook Uni - installed 1333MHz RAM, after a couple of months - keyboard failed - almost bought a new keyboard - decided to install original spec RAM before I take it in for service - keyboard starts working - installed the 1333MHz RAM - Keyboard is dead.

Late 2011 Macbook Pro - installed G.Skill MAC specific 1600MHz RAM - Crashes a few times a day. Installed 16GB Patriot Mac Series 1333MHz - Not one issue since.

You may sometimes be lucky using overspec RAM - it will not however, guarantee that it will work in the long run - if you think that it' works for you with no issues - then go ahead and use it.

Good luck

Awesome reply, thanks!

OK, I will send it back.

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Answer 7

Mar 21, 2013 9:57 AM in response to Rudolfensis

You're welcome.

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Answer 8

Rudolfensis Author

Level 1

60 points

Mar 21, 2013 9:58 AM in response to Bimmer 7 Series

Thanks for being polite, as well 😉

Some people don't know how to talk to others:

"It really doesn't matter what you think"

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Answer 9

Mar 21, 2013 10:02 AM in response to Rudolfensis

Don't take it personally - it's not an attack towards you . It's a common thread (installing over spec RAM) that we see here all the time and it does get tiring sometimes. We all go through it. I've been called worse by someone that didn't agree with what I told him and he's blasted me a few times here.

Just enjoy your Macbook and don't worry too much about what people say - it's nothing personal since they don't know you.

Cheers.

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Answer 10

Rudolfensis Author

Level 1

60 points

Mar 21, 2013 10:05 AM in response to Bimmer 7 Series

🙂

By the way, the RAM that I bought was from Komputerbay, and on their Amazon. listing, they said:

Compatible to:

MacBook Pro 17" Late 2011 and newer

MacBook Pro 15.4" Mid 2011 and newer

MacBook Pro 15" Mid 2010 and newer without Retina display

MacBook Pro 13.3" Late 2011 and newer

MacBook Pro 13" Late 2011 and newer without Retina display

iMac 27" Mid 2011 and newer

iMac 21.5 "Mid 2011 and newer

Mac Mini Mid 2011 and newer

Turns out they are saying that just to sell, huh?

I did write to them before buying, and they said it should all be OK.

Just odd they do that.

On the other hand, Apple said that the maximum that my MacBook Pro can support is 8GB 1333MHz, but 16GB works as well, no? So that's what made me doubt Apple's specifications...

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Answer 11

Mar 21, 2013 10:12 AM in response to Rudolfensis

Yes, Amazon and Komputerbay will say that it works with your Macbook because some people have had succes in using them - but there are others that have nothing but issues.

I use to think that installing the faster RAM will benefit my computer - very true in PC terms - half and half when it comes to Macs. Which is why I started using the RAM spec'd out for my Macbook.

Apple is very conservative when it comes to their RAM specs - they always downplay the maximum RAM that can be installed in their Macbook line.

2011 Macbooks does support 16GB with no issues - been using mine for a year now. You will however, notice a little slowdown in startup time with 16GB installed as opposed to having 4GB.

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Answer 12

Rudolfensis Author

Level 1

60 points

Mar 21, 2013 10:14 AM in response to Bimmer 7 Series

Ah, interesting.

But that's exactly what I meant that confuses me: if they're conservative about their maximum RAM specs, can we not assume they are equally conservative with their MHz specs?

(I'm asking.)

So perhaps even 16 GB might not be entirely safe either, so I should opt for the 8GB?

Bimmer 7 Series wrote:

2011 Macbooks does support 16GB with no issues - been using mine for a year now. You will however, notice a little slowdown in startup time with 16GB installed as opposed to having 4GB.

Oh, really?

I've noticed that it takes way longer to sleep as well — Safe Sleep's fault, probably?

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Answer 13

John Galt

Level 10

155,822 points

Mar 21, 2013 10:14 AM in response to Rudolfensis

Rudolfensis wrote:

What are you basing that on? Source?

Apple

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Answer 14

Rudolfensis Author

Level 1

60 points

Mar 21, 2013 10:16 AM in response to John Galt

John Galt wrote:

Rudolfensis wrote:

What are you basing that on? Source?

Apple

Exactly, and the same page says that the Late 2011 can support only 8GB of RAM, when 16GB runs without (allegedly) any problems for countless people. Specialist websites have endorsed that view as well.

Perhaps the same will happen with 1600MHz -- perhaps only if Corsair or OWC bought because of better compatibility and quality?

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Answer 15

Mar 21, 2013 10:18 AM in response to Rudolfensis

If you don't need 16GB - then go ahead with 8GB. The only reason I went with 16GB is because the price difference was only $25.

Does it speed up my Macbook? Not really - Things just went faster when I went SSD.

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