4 GB RAM in Macbook? I thought this was impossible

[Shaker]

I see the following i "About the Mac" after installing my 2 new 2GBx2 SO-DIMMS in my 2 month old Macbook.

Is this a glitch and I am only really able to use 3.3GB of the 4GB that OS X is seeing?

Any thoughts?

[flopticalcube]

http://guides.macrumors.com/Understanding_Intel_Mac_RAM

Earlier Core 2 Duo machines can recognize a potential 3.3 GB (with 2 x 2 GB installed... the top 700 MB is wasted, so the practical maximum is 3 Gb with 1 x 1 Gb and 1 x 2 Gb). This is a hardware limitation.

* With 4 GB installed, these machines will report 4 GB in System Profiler, but the operating system will only use 3.3 GB.

[ricgnzlzcr]

I think it shows that you have 4gb but it only accesses 3.3gb. Test it out.

[AlBDamned]

Needs to be Santa Rosa chipset to use the full 4GB - so LED rev MacBook Pro and new silver iMac, not the MacBook, older MacBook Pro or last revision iMac.

[tmoney468]

Does anyone know why my 2.33Ghz MBP has 2x2GB sticks in it, but I can only use a full 3GB in it? I thought the limit would be 3.3GB (Yes, I know it's only .3 of a GB).

[~Shard~]

Your machine will report 4GB but the OS will only use 3.3 GB.

[FreakinSyco]

It was my understanding that MacBooks (not pros) could only do 2x1gb or 2x512mb. So can my macbook do 1x1gb + 1x2gb?

[phungy]

It was my understanding that MacBooks (not pros) could only do 2x1gb or 2x512mb. So can my macbook do 1x1gb + 1x2gb?

That is correct. Dual channel has minimal effect, enjoy the extra 1GB RAM ;)

[Multimedia]

Needs to be Santa Rosa chipset to use the full 4GB - so LED rev MacBook Pro and new silver iMac, not the MacBook, older MacBook Pro or last revision iMac.That's why some of us have been continuing to hold out for a Santa Rosa MacBook including next gen IG.

[minis2003]

i know everyone has stated that the MacBook can access 3.3GB of ram but checking on the intel website

http://www.intel.com/products/chipsets/945pm/index.htm

The 945PM express chipset: Dual-channel DDR2 667MHz Memory Support Up to 10.7GB/s of bandwith and up to 4GB memory addressability, for faster system responsiveness.

So if intel stated it can access 4gb why is the MacBook limited to 3.3gb? Is it really a hardware issue or software issue?
:confused::confused:

[tmoney468]

^It's because there is memory allocated to other devices on the laptop (video card and other I/O devices). So you can only use 4GB - whatever this amount of memory is.

[TyleRomeo]

i know everyone has stated that the MacBook can access 3.3GB of ram but checking on the intel website

http://www.intel.com/products/chipsets/945pm/index.htm

The 945PM express chipset: Dual-channel DDR2 667MHz Memory Support Up to 10.7GB/s of bandwith and up to 4GB memory addressability, for faster system responsiveness.

So if intel stated it can access 4gb why is the MacBook limited to 3.3gb? Is it really a hardware issue or software issue?
:confused::confused:

I'm very curious if someone tries to see if a core 2 duo macbook can see all 4GB in 10.5. I guess we'll find out in 10 days.

[Davvido]

What did you mean by "Earlier Core 2 Duo machines"? I have the white MacBook (Mid 2009 - the last model before the glossy one), it works in 64-bit in Mac OS X Lion (64-bit kernel and extensions: Yes). Will it access full 4 GB of RAM?

[Crosbie]

What did you mean by "Earlier Core 2 Duo machines"? I have the white MacBook (Mid 2009 - the last model before the glossy one), it works in 64-bit in Mac OS X Lion (64-bit kernel and extensions: Yes). Will it access full 4 GB of RAM?

Check the dates on this necrothread.

[Davvido]

I did and I don't think it's the reason to post a new thread about it. You can answer here as well. :)

[mdgm]

I did and I don't think it's the reason to post a new thread about it. You can answer here as well. :)

I don't think you're limited to 4GB RAM. Your MacBook is much newer than the ones referred to earlier in this thread.

Go to the Command Menu (has apple symbol on it) and select "About This Mac", then click More Info. You should now be in System Profiler. What MacBook revision does it say you have (e.g. my 07 MacBook is a MacBook2,1)?

[Davvido]

MacBook5,2

[makinao]

Davvido: I've got a macbook5,2. 10.6.6. It can use all of 4GB.

[Davvido]

Thank you. Now I know what is gonna be my next purchase. :)

[bkboy]

Hi all,

I recently purchased 2 x 2gb crucial ram 1066mhz for my MACBook mid 2010 i think or late 2009. cant remember . should be the same thing ?
anyway my main question is,
I replaced the 2 x 1 GB ram with the new crucial ram. When i boot, the bios beeps continuously while the system doesnt boot.
However when i place one 1 x1 Gb ram and 1 x 2GB ram, the system boots and recognises the new ram.
Is there a reason for this? how do i get about solving iT?

Cheers,

First time mac user.

[macduke]

Hi all,

I recently purchased 2 x 2gb crucial ram 1066mhz for my MACBook mid 2010 i think or late 2009. cant remember . should be the same thing ?
anyway my main question is,
I replaced the 2 x 1 GB ram with the new crucial ram. When i boot, the bios beeps continuously while the system doesnt boot.
However when i place one 1 x1 Gb ram and 1 x 2GB ram, the system boots and recognises the new ram.
Is there a reason for this? how do i get about solving iT?

Cheers,

First time mac user.

Why does everyone keep resurrecting this four year old necrothread?

Did you try both sticks of the new ram separately? One of them is probably DOA. I'd try to RMA it or something, whichever one is bad.

If both sticks work fine, then try them in different slots. Do both slots work when you install your old memory back in? If they don't, you might have a bad slot now, but this seems unlikely.

You might also check to see if something got into one of the slots, or if you are inserting them all the way. Check to see if they are seated properly.

Always remember to touch some grounded metal to discharge static electricity before doing stuff inside any computer. Or you might fry a thing.