Need your help with a laptop memory

Nov 28, 2010
22,684
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located
Normally it does, but the CL11 RAM seems to have issues with the MBP, or the MBP has issues with CL11 RAM:

Conclusion about RAM stability:
(to sum up the part of this thread and save your time)

1) People noticed kernel panics and other instability issues with CL7 and CL11 RAM.
CL9 is 100% stable, and also the Apple's stock RAM is CL9.

2) I couldn't find any information about CL8 stability on 2011MBPs
(neither on MacRumors, nor in Google; probably because CL8 SO-DIMM RAM is pretty uncommon)
So, let's agree that CL9 is the lowest stable latency in our case
(we will become 100% sure about that only after we get info about CL8 stability)

3) Theoretically, 16GB of 1866MHz CL9 would be the best possible kit you could put inside your MBP.
Unfortunately, it will not become available until 2013-2014.
from this quite long thread
 
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AppleMacFinder

macrumors 6502a
Dec 7, 2009
795
142
Unfortunately, this is CL11. To avoid the potential problems (kernel panics),
you should buy something that is CL9: 1333MHz (slightly cheaper) or 1600MHz (faster)

I have 1600MHz CL9 (9-9-9-24) Corsair Vengeance 8GB kit (CMSX8GX3M2A1600C9)
and my benchmarks are about 15% faster than Apple stock RAM :cool:

That RAM is 1600MHz, and your Mac takes 1333MHz. Something like this is what you want.
MBP 2011 models support up to 16GB 1600MHz RAM. As I said earlier, CAS latency should be equal to 9.
 
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Stooby Mcdoobie

Contributor
Jun 26, 2012
821
36
MBP 2011 models support up to 16GB 1600MHz RAM. As I said earlier, CAS latency should be equal to 9.
I thought I read somewhere that the 2011 models clocked the RAM back down to 1333MHz if you go to 1600MHz, or is that just the 13" model? Or was I misled completely?
 
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AppleMacFinder

macrumors 6502a
Dec 7, 2009
795
142
I thought I read somewhere that the 2011 models clocked the RAM back down to 1333MHz if you go to 1600MHz, or is that just the 13" model? Or was I misled completely?
That depends on CPU which is inside your Macbook Pro.
If CPU does not support 1600MHz RAM, it will be downclocked to 1333MHz.
The information about memory support could be found on Intel website (ARK page)

Screen size | Early 2011 ......... | Late 2011 .......... | Mid 2012 ........... |
13" ....... | 2410M/2620M ........ | 2435M/2640M ........ | 3210M/3520M ........ |
15" ....... | 2635QM/2720QM/2820QM | 2675QM/2760QM/2860QM | 3615QM/3720QM/3820QM |
17" ....... | 2720QM/2820QM ...... | 2760QM/2860QM ...... | -------------------- |


Marked CPU models support up to 1600MHz and 32GB RAM
Other CPU models support up to 1333MHz and 16GB RAM

As you see, there are no 13" 2011 models that support 1600MHz RAM :(

For more interesting information, please check the Buying RAM guide
 
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mortenjensen

macrumors regular
Mar 19, 2012
221
16
That depends on CPU which is inside your Macbook Pro.
If CPU does not support 1600MHz RAM, it will be downclocked to 1333MHz.
The information about memory support could be found on Intel website (ARK page).

Please check the table below. Only bold & underlined CPU models support 1600MHz RAM.

Screen size | Early 2011 ......... | Late 2011 .......... | Mid 2012 ........... |
13" ....... | 2410M/2620M ........ | 2435M/2640M ........ | 3210M/3520M ........ |
15" ....... | 2635QM/2720QM/2820QM | 2675QM/2760QM/2860QM | 3615QM/3720QM/3820QM |
17" ....... | 2720QM/2820QM ...... | 2760QM/2860QM ...... | -------------------- |


As you see, there are no 13" 2011 models that support 1600MHz RAM. :(
How do you find out, which model number you have? It is not listed, as I can see, in the system specs.

Only something like:
- Macbook pro, 2.2, intel core i7.

Mine is late 2011, 15'' - but what is the exact number?

Morten
 
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