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macrumors newbie
Original poster
Oct 10, 2010

Please see the below which I sent to the vendor from where I purchased 16GB for each of my MBP's, the story explains itself. This may shed some light for other guys who have experienced similar situations.

Best regards & thx



First this is not a complaint or noise, just a technical update so you know what happened, probably it can be helpful for your future customers.

I have 2 x MacBook Pro's 2011 model,

1 x MacBook Pro 13" i7 DC 2.7 with Intel graphics
1 x MacBook Pro 15" i7 QC 2.3 with AMD6750M + Intel graphics

I ordered from you a couple of weeks ago 2 x kits of 16GB [2x8GB] of CSX memory, received it a few days ago and put 1 kit in the MBP 13, and the other in the MBP15.

The MBP 13 is fully stable, we use it nonstop for final cut production - no issues.

The MBP 15 is on the other hand, fully unstable. Crashing at random, and cannot complete any benchmark or load test, ESPECIALLY if it has to do with graphics. e.g., it will crash when doing any 3D or video work almost immediately. This also in Windows, as soon as any graphical 3D type application starts working or rendering, system will crash with "AMD Driver has stopped responding, restarted driver" - Mac OS X has no such functionality, so when it crashes the system just blows out with everything still sitting on the display, mouse moves around, but no response to click, impossible to logon to SSH either. e.g. FUBAR status.

So, I thought - OK - let's diagnose.

a) I put the original 2 x 2GB 10600S (apple) modules back in the MBP 15 - fully stable again, no crashes, even after !! 40 hours of the Far Cry 2 benchmark running loops over and over again, all temps were 90-95C during this 40 hours - not a single crash or problem.

b) I swapped then the memory 16GB from the working, fully stable MBP 13, into the crashing MBP 15

c) tried all testing again, fully expecting the MBP 13 to start crashing, and the 15 to be stable.

Guess what -

MBP 15 was crashing again exactly the same way with the 16GB RAM from the MBP 13.

So - synopsis:

* MBP 13 is fully operational / stable with the CSX RAM (16GB)
* MBP 15 is NOT stable with the CSX RAM (16GB)

Therefore, I ordered and paid for Samsung 16GB kit (2x8GB) for the MBP 2011, hopefully this will work.

Fortunately I was able to put the extra kit of 16GB (CSX) into my wife's 13" i5 2011 MBP, and it works absolutely fine and stable.

Very strange, I know it seems like the MB 15 has hardware failure, but it doesn't - it works absolutely normally with the original 2 x 2GB memory from Apple, and with the original 2 x 4GB 10600S from an iMac 27 I have.

It seems weird that a memory DIMM can cause the ATI card to stop functioning. The really funny thing is that if I use gfxcard control to force integrated only, the 16G 15" would work absolutely perfectly for days. I think it's because the ATI card uses memory from the system as well over and above it's 1G built in memory.

Hopefully the Samsung modules (which cost twice as much) will work.

Best regards guys


macrumors 68020
Jul 23, 2011
If only you could run CPU-Z and show us the SPD and memory pane. That would tell a lot about RAM timings, one of the prime culprits of instability.
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