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New MacBook Pro Does Not Support 8GB RAM (for now)

the macbook pro's have never been able to support 2 4GB sticks, 1 4GB + any other is okay though. I believe the new models suffer the same problem.

Hopefull this will be ironed out by the core i7 macbook pro update down the line, thats when I'm planning my next purchase hopefully a 3.0GHz Calpella, 8GB, quad-core, 512 video card Macbook Pro with Snow Leopard pre-loaded, oh how sweet that sounds.
 
i would expect this to be ENABLED in a future point release of 10.5 (possibly 10.5.6). Definitely I see this being enabled in Snow Leopard (understandably this would be an older model of the MBP at that time, but WILL be enabled). It's a simple software update. They may skip allowing this feature in Leopard because they may need to modify underlying frameworks of the OS, for example when they rewrite Snow Leopard.
 
commander.data said:
As others have said it's probably something to do with the current EFI version. 4GB DDR3 SODIMMs aren't common right now so Apple probably hasn't validated the EFI to make sure it's compatible with memory that's on the market. As such, support for RAM greater than 4GB is not enabled to ensure stability. As more 4GB SODIMMs come to market Apple will probably validate and enable 8GB support. Although it wouldn't surprise me if they'll save 8GB support in the 9400M chipset for a later refresh and not enable it on current models.

Another possibility is that the 9400M chipset supports 8GB, but seeing that Apple got first dibs and launched their products before nVidia themselves launched the 9400M chipset for OEMs, the versions that Apple uses may be early revisions that have issues with more than 4GB of RAM which is why it's disabled.
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Apple would likely charge for the update as they did with the draft n update.
 
AidenShaw said:
To me, this seems pretty silly.

Why would you "expect" the system to support more memory than advertised?
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If you have bothered to read any of the previous 3 pages, you would learn that the MBP's are "capable" of running with 6 GB of RAM; while advertised on apple.com, it says that they "support up to 4 GB" of RAM.
 
This is DEFINITELY a reason why a lot of people won't buy MacBook Pros now. Hopefully Snow Leopard will change this all though...
 
dizastor said:
Unfortunately, I think all of these little tidbits are building to become the 'value' in snow leopard.

The dual video cards, the max ram... possible only available if you shell out $129 for snow leopard. :(
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Torrents to the rescue =p
 
AidenShaw said:
To me, this seems pretty silly.

Why would you "expect" the system to support more memory than advertised?
Click to expand...

Historically Apple has advertised their machines as supporting 1/2, or even 1/4 as much as they're actually capable of. The PowerMac 9600 for example was advertised as 768 MB when it was capable of 1.5 GB (12x128 MB DIMMS). The original Beige G3 Desktop was advertised as supporting only 192 MB but it could support 768 MB. There were just no 256 MB low-profile DIMMs at the time.

Like the PM9600/Beige, the chipset of the MBP supports 8 GB.

So it's not really that silly.
 
commander.data said:
Then I guess Apple needs to do what I said in my original post and hard code a 7GB limit in the EFI for the 9400M chipset.

My current Merom Napa Refresh MacBook Pro only supports 3GB, but it's currently equipped with 2x2GB DDR2-667 CL4 memory. I've experienced no stability issues so OS X clearly can figure out how to use part of a DIMM (3GB of out 4GB in my case and presumably 7GB out of 8GB in the 9400M case) as long as the EFI prevents the device addresses range from overlapping the RAM.
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I see where you (and some others) are coming from, but the 4GB limit for pre santa rosa MacBooks which effectively gave 3GB thereabouts does not necessarily apply to the next multiple of 4GB, i.e. 8GB.

The 4GB limit was the memory limit for 32-bit stuff - chipsets and OS, as 4GB is the memory limit than 32 bit can address. So once the 4GB hurdle has been cleared, I guess with both 64-bit OS and chipset (or with physical address extensions), the new limit would be the limit for 64 bit stuff (assuming the BIOS or EFI is up to scratch). From wikipedia, the new limit is 16 exabytes of RAM or 17.2 billion gigabytes. The article did mention that since there isn't a pressing need for that much RAM, current addressing capacity is around 40 or 48 bits which even without calculating is, I'm sure, way more than 8GB.

So my guess is that the EFI and/or OS is not up to scratch here. Nvidia has already said that the chipset supports 8GB of RAM.
 
gnasher729 said:
My theory which would explain the observations so far: The motherboard can address 8 GB, but the graphics cards use addresses at the end of those 8 GB.
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Sounds like this may be the case. To the original poster:

Can you run an "ioreg -l | grep Memory" from Terminal? This should show at least some of the memory ranges used by the hardware. Plug a few into Calculator and convert to hex. On my Mac Pro (10GB), everything seems to be mapped into the very top of the 64-bit range (0xFFFFFFFF00000000 and up).

If there is a conflict with MMIO and > 4GB ram, we should see some addresses between 0x00000000FFFFFFFF (4GB) and 0x00000007FFFFFFFF (8GB).
 
gnasher729 said:
My theory which would explain the observations so far: The motherboard can address 8 GB, but the graphics cards use addresses at the end of those 8 GB. When you start the machine, the OS counts two things: How many RAM chips do you have, and how many are usable. With 4+4GB, there are two RAM chips with a total of 8 GB, but the second is not usable because it interferes with the address space of the video card, so only 1 chip = 4GB are useable. With 4+1 GB, both chips are usable, so you see 5GB and can use 5GB. With 4+2 GB, you would be able to use 6 GB. If there were 3GB chips, you would be able to use 4+3 GB.

If you have 4+4 GB, you will probably get lots of page-in/page-outs when you exceed 4GB, because the second chip is counted as free memory, but will never be used.
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if this was the case, wouldnt they be able to use it by disabling the discrete graphics, or popping it in the new macbook?

try that ifixit?
 
ifixit said:
Interestingly, when we booted Ubuntu on the machine it only reported 3 GB memory total. We don't have an explanation for that.
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Were you running 32-bit Ubuntu? That would explain the 3GB limit. You'll need 64-bit Ubuntu to see more than 3GB and change.

ifixit said:
We then added a 1 GB chip for 5 GB total. We were able to get GUI apps to use all 5 GB and the system hasn't crashed on us yet. It will take more testing to determine how stable this configuration is.
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Can you also test 6GB (1x4GB + 1x2GB)? Those of us with 6GB Santa Rosa MBPs would be comforted to know that, at least, buying a unibody MBP would not be a RAM *downgrade*.

On behalf of all RAM hogs, I thank you for your efforts! I won't forget these experiments next time I need to buy Mac parts.
 
Please read this 'data got it right!

commander.data said:
Well both Tiger and Leopard aren't fully 64-bit operating systems. The kernel is still 32-bit. A 64-bit kernel won't arrive until Snow Leopard. Tiger and Leopard can control more than 4GB of RAM because it uses PAE which allows the 32-bit architecture to address 64GB (36-bit) worth of RAM.
Click to expand...

People need to read the above because it reflects reality. MacOS is very much a hybrid 32/64 bit system. If MacOS was fully 64 bit they wouldn't be putting so much effort into getting Snow Leopard to support full 64 operations.

In any event what is happening on the new MBP is an open question. Unless someone reads the chipset manual you really don't know what or how it supports 64 bit addressing. Honestly though I don't think Apple will get to worked up about it as Snow Leopard would be the logical place to firm up 64 needs.

Dave
 
alphaod said:
Lovely; a firmware limit. This makes the old MBPs better.
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...except the new ones can support 6Gb, just like the old ones...

and also, the new ones are DDR3.........




wizard said:
People need to read the above because it reflects reality. MacOS is very much a hybrid 32/64 bit system. If MacOS was fully 64 bit they wouldn't be putting so much effort into getting Snow Leopard to support full 64 operations.

In any event what is happening on the new MBP is an open question. Unless someone reads the chipset manual you really don't know what or how it supports 64 bit addressing. Honestly though I don't think Apple will get to worked up about it as Snow Leopard would be the logical place to firm up 64 needs.

Dave
Click to expand...


this makes the most sense so far
 
OF COURSE it does not support 8 GB of RAM. There are still 2 Events left for this :D LOL Next Event = New MBP with 6GB RAM.......NEXT EVENT: Newer MBP with 8 GB RAM....

Look at the most upgrades and open your eyes....they even celebrate an event and call it an upgrade if the next MBP uses a black instead of a white power cable and people are stupid enough to buy a "new" machine. that's Apple politics.
 
You guys are speaking like it's fact that the system won't support 8gb. Clearly it is capable of reading it.

Why doesn't somebody just boot 64bit windows or linux already and see if it is still operating slowly or not and then we'll have our answer. If it's still unstable and slow then maybe it won't ever work unless a firmware update is released. If it works at normal speed, then we just have to wait for an OS update.
 
Macintosh is clearly a highend system. OSX is still 32bit and AU$4000 laptops just support up to 4GB. The system is just a joke.
 
dal20402 said:
Were you running 32-bit Ubuntu? That would explain the 3GB limit. You'll need 64-bit Ubuntu to see more than 3GB and change.
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Exactly!

Please can people do some research before attempting something rather than spread fud?

To test if the macbook hardware can handle 8GB use a true 64bit OS, bootcamp with Vista 64bit or Linux 64bit. The OSX kernel is still 32bit, so it's no surprise that it was limited to 4GB.

At ifixit team... this will explain things.
http://en.wikipedia.org/wiki/Physical_Address_Extension
 
Hi Luke,

ifixit said:
Interestingly, when we booted Ubuntu on the machine it only reported 3 GB memory total. We don't have an explanation for that.
Click to expand...

Did you boot the 64-bit version?

We then added a 1 GB chip for 5 GB total. We were able to get GUI apps to use all 5 GB and the system hasn't crashed on us yet. It will take more testing to determine how stable this configuration is.
Click to expand...

Will you try a 4+2 configuration? That's what I am considering (and read others had success with in their SR MBPs).

Boris
 
It's funny to read all these 'Snow Leopard' comments by users.
Peeps, it's gonna take some time before that will be in effect.
And usable in a pro-work area.
And don't get your hopes up too high.
Like I did with this cripled machine.
 
Btw. when I was deciding for a new laptop in summer 2007, I was considering 2 options: Thinkpad T61(p) and MBP. I thought Thinkpad is better engineered and a very solid machine, but chose MBP since I thought the same holds for the Professional MBP, and it has better software (iLife etc.). Now I see I had better gone with the Thinkpad, I could be running 8GB without problems (as reported on the famous post). And it would cost just $1335, instead of $2000 for MBP, and include better screen resolution (i.e. 1680x1050 instead the 1440x900).
 
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