Got a tip for us?
Let us know
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Can I Upgrade up to 12GB?
- Thread starter D4RTH
- Start date
- Sort by reaction score
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.
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
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
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.
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).
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.
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?
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.
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.
The benefits of more outweigh the benefits of matched. Of course, more matched RAM is the best.
That's the exact kind of clever, well thought and completely attinent comparison one would expect when investigating technical contexts.
Thanks for your contribution.
Non recommended because it isn't pretty?
Why exactly, in what exact tasks and precise context would that not be recommended?
Why would that be better?
It doesn't have to be pretty. It's RAM, for Drake's sake.
When will we get a MacBook Pro that allows 24GB or 32GB of RAM? Too bad that the latest release doesn't.
when they make 12GB and 16GB modules that fit the MBP
even a 2011 MBP would allow it but those modules do not exist
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.
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???
----------
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).
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.