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ayeying

macrumors 601
Original poster
Dec 5, 2007
4,547
13
Yay Area, CA
THIS IS FOR BOTH DDR2 AND DDR3 SYSTEMS. ALL INFO HERE APPLIES TO BOTH DDR2/DDR3 SYSTEMS. HOWEVER, DDR2 SYSTEM CAN ONLY USE DDR2 CHIPS. SAME GOES TO DDR3 ONLY USING DDR3 CHIPS

Okay, I'm going to clear up some of the questions for this since it appears there is SOOOO many threads being created about this.

YES 6GB WORKS IN THE MACBOOK & MACBOOK PRO & IMAC EVEN IF APPLE SAYS THEY DON'T OFFICIALLY SUPPORT IT.

8GB WORKS BUT THERE IS A FEW ISSUES ON OLDER MODELS

You have 2 options above 4GB:

6GB (1x2GB/1x4GB)
8GB (2x4GB) (Usable on newer Unibody systems)

Newegg has the cheapest price. The links are below:

Single stick of 4GB DDR2 -
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231202

Dual stick of 4GB DDR2 (total of 8GB) -
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231210

FAQ:

Will my MacBook (Pro) support up to 6GB?
- Only the Penryn (MacBook (Pro) 4,1) can support this much memory. The MacBook (Pro) 2,1 only supports upto 3.25GB ram accessible so adding in 6GB wouldn't matter since you can only access >4GB.

Update: New MacBook Pro(s) can support 8GB. As of September 2, 2009, the following systems support 8GB ram:

MB604*/A – 17” Unibody MacBook Pro, Early 2009 2.66GHz
MB990*/A – 13” Unibody MacBook Pro 2.26GHz
MB991*/A – 13” Unibody MacBook Pro 2.53GHz
MC118*/A – 15” Unibody MacBook Pro, Base Model 2.53GHz (Single Video Card)
MB985*/A – 15” Unibody MacBook Pro, Mid Range 2.66GHz (Dual Video Card)
MB986*/A – 15” Unibody MacBook Pro, High Range 2.8GHz (Dual Video Card)
MC226*/A – 17” Unibody MacBook Pro, 2.8GHz
MC026*/A – 15” Unibody MacBook Pro, Early 2009 2.66GHz (Dual Video Card) Note: This is only stated on Apple’s website, has not been confirmed
Note 2: I did not include the CTO models, but if you fall into the category of those pre-built, you can use 8GB ram

- Currently, OSX Leopard (10.5.x) seems to have trouble accessing above 6GB of physical ram. Further testing is being done, but currently, 6GB is the max that is considered "safe".

Update: This is determined as a Firmware problem, not OS. No matter if you’re using Leopard or Snow Leopard or 64-bit Kernel, it will crash with 8GB unless the models specified above.

How do I know when my MacBook Pro was purchased?
- Read this: http://guides.macrumors.com/MacBook_Pro
If you fall into Rev D or Rev E specs (or Unibody MacBook Pro 15"), you can support up to 6GB w/o problems. 8GB is only allowed on the Unibody MacBook Pro 17" currently.

Update: All 13” Unibody MacBook Pro’s allow 8GB. 15” Unibody MacBook Pro’s starting at 2.66GHz Rev F (untested for Rev. F, Rev. G is confirmed) allow 8GB. All 17” Unibody MacBook Pro allow 8GB.

How do I know when my MacBook was purchased?
- Look here: http://guides.macrumors.com/MacBook
If you fall into Rev D or newer, you can support up to 6GB w/o problems.

If I add 1x4GB and 1x2GB, totaling 6GB; or just using 1x4GB; do I lose dual channel?
- Yes, you do lose dual channel.

Is losing Dual Channel a huge performance hit?
- Not really. It all depends on what you use it for. If you're doing a lot of modeling/rendering, dual channel might be a great help. For an average user or someone who runs memory hungry apps such as Virtual Machines, it is not much of an hit.

Isn't Leopard (10.5.x) 32-bit?
- Yes and No. Leopard uses both 32 and 64-bit framework. It is not entirely just 32-bit therefore it can access and use all the 4+GB ram. Unlike Windows XP (for example) it is completely 32-bit and cannot read/write/access anything above 4GB. If you don't believe me, its on Leopard's page on apple.com.

Isn’t Snow Leopard (10.6.x) a 64-bit OS?
- Yes, but that doesn’t mean you can use 8GB. If you can use 6GB, then it’s not a 32 or 64-bit problem. It is not a 32-bit or 64-bit kernel problem either. Extensive testing has determined this is a problem with the firmware, not OS.

Will 6/8GB be supported on systems other then MacBook Pro and Mac Pro?
- Currently, my dad's iMac Rev. C is capable of running 6GB. He is using 6GB currently that was pulled from my old Penryn MacBook Pro.
Refer here to see which Rev you fall under:
http://guides.macrumors.com/iMac_(Intel)

What type of issues 8GB users are having?
- Read page 4+ ; Accessing memory above 4GB seems to cause OSX to throw the extras into swap, making the rest of the 4GB Actual useless.

Update: This only refers to Early 2008 Unibody MacBook Pro (15” Models only), 13” Unibody MacBook, 13” Polycarbonate MacBook, and late Discrete MacBook Pro (15 and 17”) models.

Why is there a difference in the prices between G-Skill and Crucial?
- I don't know. All I know is that the many users who have purchased G-Skill, their ram works well. If you're the type of person who believes more expensive = better, go right ahead. I'm just posting the cheapest price available and the same type of memory I personally use.

Why is only the new Unibody MacBook Pro 17" able to use all 8GB?
- Blame Apple.

Update: Not anymore.

What systems can use what amount of ram?
- Currently, these systems are confirmed:

Intel Xeon Mac Pro systems can use 16GB (Rev A) and 32GB (Rev B)
Mac Mini can use 3.25GB for Core 2 Duo models and 2GB for Core Duo models
Rev C or above Intel iMac systems can use 6GB.
[Update] Starting 2009 Models, all iMac can use 8GB
Rev D or above Polycarbonate (Plastic) MacBooks can use 6GB
Rev D or above MacBook Pro (15/17") can use 6GB
Unibody MacBooks can use 6GB
[Update] Late 2008, Unibody MacBook Pro 15" 2.53GHz or Higher and Mid 2009, All Unibody MacBook Pro 15" can use 8GB
Unibody MacBook Pro 17" can use 8GB
MacBook Air Rev A or Rev B can use 2GB (soldered)
 
Last edited:

Aranince

macrumors 65816
Apr 18, 2007
1,104
0
California
Is there a difference between using 2x2Gb or 1x4Gb memory stick? I assume price is a factor, would speed be a factor?
 

HiFiGuy528

macrumors 68000
Jul 24, 2008
1,874
64
What are the benifits of 8GB RAM if the OS@ 32bit can't use it all? Are there tests done that shows improvements?

Are you talking about the all current models?

Keith Comb's
http://blogs.technet.com/keithcombs...n-t-like-8gb-of-memory-in-my-macbook-pro.aspx

"[UPDATE for 7/11] I configured my Mac for bootcamp and installed Windows Vista Enterprise x64. I also installed Windows Server 2005 R2 SP1 x64 and ran three virtual machines with the 4GB of system memory configuration. No issues. That ran well. I shut things down gracefully and installed the two Kingston 4GB sticks bring the total system memory up to 8GB. The machine would barely boot Windows Vista and run. It is now apparent to me the memory sticks I have have some sort of incompatibility with the MacBook Pro I have. My testing of this has now concluded. It’s up to Kingston and Apple to resolve".
 

ayeying

macrumors 601
Original poster
Dec 5, 2007
4,547
13
Yay Area, CA
What are the benifits of 8GB RAM if the OS@ 32bit can't use it all? Are there tests done that shows improvements?

Are you talking about the all current models?

This is an interesting question because it is near certain (in my opinion) that this should work for the MacBook (not Pros) and iMacs also.

ayeying you could make a MacRumors Guide on this subject. ;)

I know. But honestly, many newbies here just post without reading the guides. lol
 

Cave Man

macrumors 604
What are the benifits of 8GB RAM if the OS@ 32bit can't use it all? Are there tests done that shows improvements?

Leopard is 64 bit.

Are you talking about the all current models?

MBP, MB and iMac, but not the Mini.

Keith Comb's: "It’s up to Kingston and Apple to resolve".

The problem appears to be Kingston's chips, because my G.Skills seem to work just fine.
 

squeeks

macrumors 68040
Jun 19, 2007
3,393
15
Florida
8GB??? If you have 8GB memory in your MacBook Pro then you're dead spoiled:rolleyes:

for $320 bucks? thats not spoiled, owning a MBP in the first place is spoiled, you buy a 2k - 2.5k notebook but adding an extra 300 bucks to it makes you spoiled? i dont follow your reasoning...

btw BOUGHT :D
 

ayeying

macrumors 601
Original poster
Dec 5, 2007
4,547
13
Yay Area, CA
damn. everyone's buying those sticks. I was planning on getting another 4GB stick to up my system to 8GB.
 

duykur

macrumors regular
Jan 20, 2008
101
0
since i am using a laptop whith 496mb (yes 496mb) of ram i can't even imagine how fast 8 gb would be...
 

SchneiderMan

macrumors G3
May 25, 2008
8,332
202
can this work on a hp that says its only up to 2gb? i want to get 4gb ram on it. i have 2gb only now
 

ayeying

macrumors 601
Original poster
Dec 5, 2007
4,547
13
Yay Area, CA
can this work on a hp that says its only up to 2gb? i want to get 4gb ram on it. i have 2gb only now

There's no reason not to if the hardware is compatable you ahve a good chance of making it work. Having a compatable BIOS might be a different story.
 
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