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irishgrizzly

macrumors 65816
Original poster
May 15, 2006
1,461
2
I've got a new 4gb stick to replace one of my 2gb. Does it matter which slot(Upper/lower) it goes in?
 
Nope. I have one 2GB and one 4GB module in my 2009 MBP. All you lose is some speed gain due to two identical RAM modules being a bit faster (10%).

And to the OP: It doesn't matter.

Never put two different memory modules into the same computer. Always use identical RAM and as part of a kit. This is not recommended and will prolong the use of your laptop. It may cause certain hardware issues and faults with the computer.

As far as which slot you should put it in, it does not matter as long as its supports that memory module.
 
Never put two different memory modules into the same computer. Always use identical RAM and as part of a kit. This is not recommended and will prolong the use of your laptop.

As far as which slot you should put it in, it does not matter as long as its supports that memory module.

Does that mean that everyone who does that (and there seem to be a lot of people doing that) will shorten the life of her or his Mac? How?
 
Does that mean that everyone who does that (and there seem to be a lot of people doing that) will shorten the life of her or his Mac? How?

It won't, typically, DDR3 based systems can address memory modules in banks of 1, 2 or 3. If a system supports it, installing memory in matched sets of 2 or 3 modules (dual channel or triple channel modes) will deliver greatly increased memory performance over running a single memory module by itself.
 
Nope. I have one 2GB and one 4GB module in my 2009 MBP. All you lose is some speed gain due to two identical RAM modules being a bit faster (10%).

And to the OP: It doesn't matter.
Never put two different memory modules into the same computer. Always use identical RAM and as part of a kit. This is not recommended and will prolong the use of your laptop. It may cause certain hardware issues and faults with the computer.

As far as which slot you should put it in, it does not matter as long as its supports that memory module.

That somehow conflicts what you wrote earlier.
Does that mean that everyone who does that (and there seem to be a lot of people doing that) will shorten the life of her or his Mac? How?
It won't, typically, DDR3 based systems can address memory modules in banks of 1, 2 or 3. If a system supports it, installing memory in matched sets of 2 or 3 modules (dual channel or triple channel modes) will deliver greatly increased memory performance over running a single memory module by itself.

And as far as I can gather through posts and benchmarks, dual channel is not significantly faster. Once I will upgrade to 8GB RAM in my MBP I will test further.
 
more or larger RAM modules

I believe the new iMacs are dual channel. (correct me if I am wrong)
That being said it is better to have more modules or larger RAM modules:
2 x 4GB
or
4 x 2GB?
 
Wow this thread is a mess.

1. You can install the RAM into either slot. I SUGGEST you put the 4GB in the bottom slot so that when you want to upgrade to 8GB it will be easier to access the 2GB chip.

2. Size or matched pair does NOT matter(conditions to follow) and will NOT hurt your system.

2a. Matching the memory will enable Dual Channel that will let the RAM work faster, but will not "greatly increase"

2b. Depending what you are doing having the extra RAM can help you more than having faster RAM.
 
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