Can I Upgrade up to 12GB?

D4RTH

macrumors newbie
Original poster
Jan 21, 2014
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I have macbook pro 13" mid 2012. Currently rolling with 4gb 1600mhz ~_~. So I was wondering if i can add 8Gb 1600mhz and 4GB 1600mhz together = 12GB?
 

8080532

Suspended
Apr 7, 2013
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I have macbook pro 13" mid 2012. Currently rolling with 4gb 1600mhz ~_~. So I was wondering if i can add 8Gb 1600mhz and 4GB 1600mhz together = 12GB?
I've read that it isn't recommended to have mismatching ram. Ex 4gb and 8gb to equal 12. I would go with 4 and 4 or 8 and 8
 
Nov 28, 2010
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I've read that it isn't recommended to have mismatching ram. Ex 4gb and 8gb to equal 12. I would go with 4 and 4 or 8 and 8
It is not recommended due to two differing modules not supporting dual channel model, which give a slight speed increase during RAM intensive tasks, but running two different modules is not harmful.
 

raptor402

macrumors 6502
Jun 30, 2011
399
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I have macbook pro 13" mid 2012. Currently rolling with 4gb 1600mhz ~_~. So I was wondering if i can add 8Gb 1600mhz and 4GB 1600mhz together = 12GB?
I'm assuming that you have 2*2GB. If you want to upgrade to 12GB, you'll definitely have to buy 2 new DIMMs. You might as well go for 2*8GB for a proper Dual Channel setup. It will cost you around $25 more (less than 25% more).

If, however, you are getting a good deal or are obtaining one DIMM from elsewhere, you should go ahead.

Raptor
 

8080532

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Apr 7, 2013
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It is not recommended due to two differing modules not supporting dual channel model, which give a slight speed increase during RAM intensive tasks, but running two different modules is not harmful.
Back to OP, would you want your right arm to be bigger than your left? Or would u like both to be equally strong and same size!
 

Laco

macrumors 6502
Apr 23, 2008
375
1
Back to OP, would you want your right arm to be bigger than your left? Or would u like both to be equally strong and same size!
Most people have different strength hands. I am right handed so my right hand is stronger than my left :)
 

maflynn

Moderator
Staff member
May 3, 2009
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That's pretty non-standard and not recommended.

Recommended values are power of 2 values like 1, 2, 4, 8, 16, 32...etc.

So you should go for 16GB.
It is nonstandard but it is technically feasible but I agree, its better to use matched pairs.
 

brdeveloper

macrumors 68020
Apr 21, 2010
2,472
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Brasil
I would only use 12GB if, for example, someone discovered that Late-2008/2009 Macbooks can't use 16GB, but they work flawlessly with 12GB. I never saw this kind of affirmation, though, but I would upgrade to 12GB if my white mac supported, so I could load more stuff into ram, which is always good if you need dealing with a lot of data simultaneously (e.g. math computations, VMs, multitrack audio, etc).
 

drambuie

macrumors 6502a
Feb 16, 2010
751
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As long as the speed and latency of each module is the same, there will be no problem mixing 4GB and 8GB modules. The only effect is that the lower 8GB will operate in dual channel mode, and the upper 4GB, from 8GB to 12GB, will operate in single channel mode with about a 10% performance hit. That will only happen when the lower 8GB is fully utilized.
 

heisenberg123

macrumors 603
Oct 31, 2010
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I'm assuming that you have 2*2GB. If you want to upgrade to 12GB, you'll definitely have to buy 2 new DIMMs. You might as well go for 2*8GB for a proper Dual Channel setup. It will cost you around $25 more (less than 25% more).

If, however, you are getting a good deal or are obtaining one DIMM from elsewhere, you should go ahead.

Raptor
good call out I am surprised nobody else confirmed this with the OP

OP do you only 1 4GB module currently in the MBP? there is only space for 2 modules total, or do you currently have 2x4GB for a total of 8GB and want to upgrade just 1 module from 4 to 8 for new total of 12?
 

brdeveloper

macrumors 68020
Apr 21, 2010
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Brasil
As long as the speed and latency of each module is the same, there will be no problem mixing 4GB and 8GB modules. The only effect is that the lower 8GB will operate in dual channel mode, and the upper 4GB, from 8GB to 12GB, will operate in single channel mode with about a 10% performance hit. That will only happen when the lower 8GB is fully utilized.
Do you confirm this behaviour? I usually read that this "intelligent" dual-channel mode is pretty rare in most motherboards.
 

leman

macrumors G3
Oct 14, 2008
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4,564
Do you confirm this behaviour? I usually read that this "intelligent" dual-channel mode is pretty rare in most motherboards.
AFAIK, it doesn't have much to do with a mainboard nowadays as the memory controller is now part of the CPU. A single controller is responsible for a single channel and will address as much RAM as available on that channel. Using different-size RAM modules should work without any problems, the only disadvantage is that the RAM controller utilisation is less balanced. I can be completely wrong about this though.
 

disasterdrone

macrumors 6502
Aug 31, 2013
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Any small advantages of matched RAM is almost always cancelled out by the huge and real advantages of MORE RAM.

The benefits of more outweigh the benefits of matched. Of course, more matched RAM is the best.
 

LostSoul80

macrumors 68020
Jan 25, 2009
2,133
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Back to OP, would you want your right arm to be bigger than your left? Or would u like both to be equally strong and same size!
That's the exact kind of clever, well thought and completely attinent comparison one would expect when investigating technical contexts.
Thanks for your contribution.

That's pretty non-standard and not recommended.

Recommended values are power of 2 values like 1, 2, 4, 8, 16, 32...etc.

So you should go for 16GB.
Non recommended because it isn't pretty? :confused:
Why exactly, in what exact tasks and precise context would that not be recommended?

It is nonstandard but it is technically feasible but I agree, its better to use matched pairs.
Why would that be better? :confused:
It doesn't have to be pretty. It's RAM, for Drake's sake. :eek:
 

simonsi

macrumors 601
Jan 3, 2014
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Auckland
When will we get a MacBook Pro that allows 24GB or 32GB of RAM? Too bad that the latest release doesn't.
Some Macs have 4x memory slots so can get to 32GB on current 8GB modules. The issue is the MBPs only have two slots and aren't going to get any more anytime soon it seems.
 

simonsi

macrumors 601
Jan 3, 2014
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716
Auckland
The only effect is that the lower 8GB will operate in dual channel mode, and the upper 4GB, from 8GB to 12GB, will operate in single channel mode with about a 10% performance hit. That will only happen when the lower 8GB is fully utilized.
Do you mean "lower 8GB" as in the memory controller will prioritize the 8GB module? Does it have to be in slot 0 for that? Or do you mean the lower 8GB addressable, which could be 4GB in the 4GB module and 4GB in the 8GB module IF it prioritizes the 4GB module, which may be slot-dependant???

----------

It seems likely they will get fewer.
Yep, which makes development of 16GB slot-in modules (even) more unlikely.
 

leman

macrumors G3
Oct 14, 2008
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When will we get a MacBook Pro that allows 24GB or 32GB of RAM? Too bad that the latest release doesn't.
Yep, which makes development of 16GB slot-in modules (even) more unlikely.
It has nothing to do with the MBP - its the limitation of DDR3 technology. RAM developers have been trying to make higher-density DDR3 modules for years now, without success. It will never happen. We will see higher-density RAM with DDR4 and its successors.

(before someone brings it up, yes, the MBP could use 4 RAM module lanes, thus allowing it to have 32GB. Only very few laptops have that though and the increased space requirement would make the current form factor impossible. Very few users require 32Gb RAM, and Apple does not target those with the MBP).
 

brdeveloper

macrumors 68020
Apr 21, 2010
2,472
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Brasil
It has nothing to do with the MBP - its the limitation of DDR3 technology. RAM developers have been trying to make higher-density DDR3 modules for years now, without success. It will never happen. We will see higher-density RAM with DDR4 and its successors.

(before someone brings it up, yes, the MBP could use 4 RAM module lanes, thus allowing it to have 32GB. Only very few laptops have that though and the increased space requirement would make the current form factor impossible. Very few users require 32Gb RAM, and Apple does not target those with the MBP).
What about 10-12GB RAM modules? Still impossible?
 

disasterdrone

macrumors 6502
Aug 31, 2013
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(before someone brings it up, yes, the MBP could use 4 RAM module lanes, thus allowing it to have 32GB. Only very few laptops have that though and the increased space requirement would make the current form factor impossible. Very few users require 32Gb RAM, and Apple does not target those with the MBP).
Yes - no pro users need more than 16gb of ram. ;)
 

leman

macrumors G3
Oct 14, 2008
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What about 10-12GB RAM modules? Still impossible?
You will have to ask a specialist on that. AFAIK, the number of chips per module must be multiply of 8. To get 12GB you'd need 1.5Gbit chips, which is a very weird number. RAM chip makers prefer powers of 2 ;)

Yes - no pro users need more than 16gb of ram. ;)
When did I say that? I am only saying that if your work needs 32GB RAM, then Apple laptops are probably not for you. There is a number of companies selling workstation machines, why not look there? Different usages, different tools.