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

[bartzilla]

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.

Yes, but if you think about what was actually said, you'd see that the point being made was that Apple only advertise the laptops as being able to support 4Gb of RAM.

Now the fact that they appear to handle more is a nice bonus, and I'll probably upgrade mine after a while, when it arrives, but you can't really reasonably complain if you're buying something based on the "expectation" that it performs twice as well as advertised and it turns out your expectations were misguided and it "only" does half as well again as what it claims to be able to do.

Let me put it another way, if you find $10 in the street, you can't really go and complain because you've had a rough month and really could have done with finding $20.

 

[Scottsdale]

I'm sorry but I'm trying to stop the spread of FUD, as much as I acknowledge the effort ifixit have taken to test this for us they are going about doing this the wrong way much like main stream press without presenting the facts, ie. 32bit vs 64bit computing. This is dangerous and allows people like yourself to spread rumors that have no basis in fact.

Edit:
Snow Leopard if I understand things correctly will be a true 64bit OS, that means that the current macbooks and earlier will be able to support more than 4GB.

How about that the RAM costs NEARLY $1200 according to two sites I found that sell the 4 GB Modules in 1066 MHz DDR3. That is what I am talking about. Why don't you spend the money and test it yourself if you are going to complain. So, I just think you could consider what you are criticizing. Someone trying to help out and educate us all. Expensive it is. Whatever, just my two cents. I am not spending $1200. I am reading ALL of the thread and coming to my own conclusions, without criticizing someone who is spending the money and the time to try this for ALL of our benefit.

 

[LedCop]

The above is very confused! No commonly availabe 64 bit processor supports a the use of all possible address lines. Further SOME Intel processors and chipsets support a 32 bit operating mode called PAE which gives a processor 36 bits of real world addressing.

It only takes one bit to go from 4 GB to 8 GB.


The problem is Nvidia hasn't said what mode the processor has to be in to get that addressing nor have they said how the I/O space gets remapped.

Oh, come on!

The second quote of mine you restated shows how I am actually aware of your first accusation that I am "very confused because no commonly available 64 bit processor supports the use of all possible address lines..." Did I not mention current addressing capacity is around 40 or 48 bits?!

My point is that some people think just because old Intel chipsets had problems addressing 4GB RAM with about 3.25GB or so being actually available to the user that the problem should occur again for 8GB of RAM since that's the next multiple of 4GB.

This theory is made while being oblivious to the fact that the initial problem was due to 32-bit addressing limitations and so once past that 32-bit addressing problem with solutions like PAE or with true 64-bit, I don't see any reason why the hurdle of 8GB should be due to the chipset. So why as you seem to imply, should the nVidia chipset just choke at 8GB even with the I/O space that has to be taken into consideration!?

 

[jegbook]

Is Boot Camp good enough for 64 bit support?

I'm no hardware person, but from my understanding of Boot Camp is that it does some BIOS emulation. Is this right or misguided?

If Boot Camp does BIOS emulation, then it seems possible/likely that Apple's BIOS emulation also does not support 8GB of memory.

The test then would seem to be installing Vista x64 without Boot Camp. Is Ubuntu/Linux an EFI capable OS? Regardless, install an EFI capable OS on a MB/MBP with 8GB of RAM directly with no OSX/Boot Camp. That way the OS is interfacing with the hardware directly with as minimal Apple intervention as possible.

How does that sound?

 

[thesandbender]

Newbie hackintosh user... 8 gigs works for me

I'm a few days into OSX... so maybe I don't understand the problem... but I have 10.5.1 running on my intel P45 motherboard and it recognizes and uses all 8 gigs on my motherboard (4x2GB DDR2). So it doesn't seem to be an OS problem (especially considering I'm running on non-sanctioned hardware).

T

 

[parapup]

Ubuntu 64-bit or Vista x64 results PLEASE!

Ifixit - it would be really great if you can please post the results for Ubuntu 64 or Vista 64 as many have requested!

I am beginning to suspect it is the OS+Devices+Chipset combo to blame but it is primarily the way OS X does things. Apple has a kludge in the OS where it can run 64-bit apps but can still use the 32-bit drivers and no one on earth except Apple knows how the heck did they do that. No OS with sane architecture can even think of doing that kind of a thing since it involves some major hackery which slows things down a lot.

This article sheds some light . Excerpt -

"On the flip side, the kernel cannot use the
extended x86_64 register set and is restricted
to a 32 bit address space"

"..While the kernel is run-
ning, the user's data is not mapped into its ad-
dress space, and while user code is running, the
kernel is not mapped. So user and kernel can
each have 4 GB of address space with the dis-
advantage of being less efficient in copying of
data between user and kernel."

 

[parapup]

... but I have 10.5.1 running on my intel P45 motherboard and it recognizes and uses all 8 gigs on my motherboard (4x2GB DDR2). So it doesn't seem to be an OS problem

It does recognize all 8Gb in iFixit tests - the question is that is it able to actually use it all without slowing down or inducing instability? So can you run all the same tests on your hackintosh and report back here please? I am not saying it will give you same results, just very curious about the whole thing - Mac Pro obviously is able to use > 8Gb, Nvidia says 8Gb is fine for their chipset, CPU is no issue either and still it doesn't work out.

 

[ablemac]

Daul Channel issue?

It's great to have geeks push the limits and see what works so the rest of us can make informed buying choices.

I offer the observation that running a 4 Gig and 1 Gig wouldn't enable any dual channel feature of the chipset and suggest that the issue could lie in a faulty routine of the chipset, failing to handle dual 4 Gig sticks of RAM in dual channel.

Sadly I haven't played with EFI like I used to play with BIOS, so I can't offer any suggestions on running 8 Gigs in Non-Dual Channel Mode (or what ever they call it, probably single channel).

 

[ir0n]

stop speculating and run ubuntu x64 live cd on it

 

[AidenShaw]

It sounds like OS X "Snow Leopard" could very well be x86_64-only. While Apple is cleaning out the PowerPC cruft, they might as well get rid of the 32-bit code as well.

Yes - but of course that will mark the end-of-life for the 32-bit Core Duo Apple systems.

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.

Let me clarify - I said that it's silly to *expect* 8 GiB to work.

Not silly to hope, but silly to expect .

 

[BongoBanger]

Has anyone tried Vista x64?

Because that actually does support 8GB or more.

 

[Cave Man]

This is nonsense.

<snip best address yet on this topic until Apple opens up their documentation vault for all to see, which is less likely than a snow ball's (leopard's?) chance in Hell...>

Nice post.

 

[dotcommie]

Now, I am NOT a developer and know relatively NOTHING about this issue other than a few hours of reading tonight and the other day about this. I am a small business management consultant.

WHY NOT? Well, Apple is supplying drivers AND WHAT ELSE when using Boot Camp? Is Boot Camp not the answer to finding out whether this is a hardware or software limitation. When you are using the Apple hardware you are MISSING the BIOS which you normally have as the hardware/Motherboard of the PC. So, just because you install 64-bit doesn't mean it will work outside OS X either. Still NOT a hardware limitation of the Chipsets (Intel) or Nvidia GPU.

Wow. Please stop until you read for a few more hours.

EFI is essentially the bios.

Linux 64bit can be burned and booted in a few minutes and then we'll have our answer. Somebody just do it already, this is getting ridiculous.

 

[Skeletal-dæmon]

Has anyone tried Vista x64?

Because that actually does support 8GB or more.

So does OS X, otherwise how could the Mac Pro ship with 16GB (and I believe the new ones even have a 32GB option, or maybe I dreamed it)?

 

[AidenShaw]

Originally Posted by BongoBanger

Has anyone tried Vista x64?

Because that actually does support 8GB or more.

So does OS X, otherwise how could the Mac Pro ship with 16GB (and I believe the new ones even have a 32GB option, or maybe I dreamed it)?

Or even load Windows Server 2003 - the 32-bit versions support 64 GiB....

However, having an OS that can use more than 4 GiB doesn't mean that the OS has support for a new chipset like the Nvidia one in the new Apples.

Typically a hardware support layer (HAL (Hardware Abstraction Layer) on Windows) will need to turn on features of the chipset. If the Nvidia chipset doesn't claim standard PAE features, then the Windows/Linux "HAL" might only see 4 GiB, same as OSX.

 

[BongoBanger]

So does OS X, otherwise how could the Mac Pro ship with 16GB (and I believe the new ones even have a 32GB option, or maybe I dreamed it)?

Quite so. Just not on this machine apparently.

So, to repeat, has anyone?

 

[commander.data]

Ifixit - it would be really great if you can please post the results for Ubuntu 64 or Vista 64 as many have requested!

I am beginning to suspect it is the OS+Devices+Chipset combo to blame but it is primarily the way OS X does things. Apple has a kludge in the OS where it can run 64-bit apps but can still use the 32-bit drivers and no one on earth except Apple knows how the heck did they do that. No OS with sane architecture can even think of doing that kind of a thing since it involves some major hackery which slows things down a lot.

This article sheds some light . Excerpt -

"On the flip side, the kernel cannot use the
extended x86_64 register set and is restricted
to a 32 bit address space"

"..While the kernel is run-
ning, the user's data is not mapped into its ad-
dress space, and while user code is running, the
kernel is not mapped. So user and kernel can
each have 4 GB of address space with the dis-
advantage of being less efficient in copying of
data between user and kernel."

You seem to imply Apple's 64-bit transition method in Tiger and Leopard where both 32-bit and 64-bit apps are supported while the kernel is still 32-bit is not ideal. Apple's method actually makes a lot of sense since it fosters the development of 64-bit apps, while not breaking drivers and system compatibility as a pure 64-bit OS like Windows x64. When 64-bit apps are run the processor runs in pure 64-bit mode so you get all the benefits of more registers, larger address space, etc. When 32-bit apps are run the processor runs in 32-bit mode so nothing breaks, and the kernel is 32-bit also, but 36-bit PAE enabled so that it can manage up to 64GB of RAM for use by both 32-bit and 64-bit applications.

The transition method Apple uses avoids the chicken and the egg problem, where developers are reluctant to write 64-bit programs and new 64-bit drivers because there aren't enough users of 64-bit operating systems, while there aren't enough 64-bit users because there isn't the 64-bit programs to justify the switch and there aren't enough 64-bit drivers so many of your devices won't work. With a 32-bit kernel and ability to run 64-bit apps, 64-bit app development can start ahead, so that when a pure 64-bit OS with 64-bit kernel arrives in Snow Leopard there are at least some 64-bit programs to encourage users to transition so that the market is there for developers to spend time to write new 64-bit drivers and more 64-bit programs. Admittedly, in practice there isn't a glut of 64-bit programs right now, I only know of Mathematica, Cinema 4D, Chess, and XCode 3, but it's a good idea in concept.

And in 32-bit mode, the ability to devote the complete 4GB address space to an application when it is running or to the kernel when it is running instead of having a persistent kernel that takes up 2GB leaving only 2GB for applications like 32-bit Windows also makes a lot of sense. Afterall, you don't have issues on Mac like in 32-bit Windows where even games now are hitting the 2GB application address space limit and crashing. (http://www.anandtech.com/gadgets/showdoc.aspx?i=3034&p=1)

And devoting the full 4GB address space on a 32-bit OS to an application or a kernel is not an Apple only kludge as you imply. Red Hat Linux has a kernel called Hugemem which allows individual applications and the kernel to exclusively consume the full 4GB space on 32-bit processors, just like in OS X. (http://blogs.oracle.com/gverma/2008/03/redhat_linux_kernels_and_proce_1.html)

Or even load Windows Server 2003 - the 32-bit versions support 64 GiB....

That's because the 32-bit versions of Windows Server support PAE just like OS X.

PAE is actually supported in consumer versions of Windows too, but it's disabled because drivers need to be written to take it into account. Server drivers have long since standardized on PAE support since before 64-bit processors were available it was the only way to get more than 4GB of memory. There was no such demand before in consumer Windows, so consumer drivers don't support PAE and it's too late to get every driver rewritten.

When Apple transitioned to Intel, they learned from this issue and implemented PAE by default from the start. This is why there are no driver issues and Apple supports the Mac Pro running 32GB of RAM even though the Tiger and Leopard kernels are both 32-bit.

 

[Scottsdale]

I'm a few days into OSX... so maybe I don't understand the problem... but I have 10.5.1 running on my intel P45 motherboard and it recognizes and uses all 8 gigs on my motherboard (4x2GB DDR2). So it doesn't seem to be an OS problem (especially considering I'm running on non-sanctioned hardware).

T

Could you please tell me what does the system say about the computer under About this Mac? Go into more info, in System Profiler see what "Model Name" and "Model Identifier" are listed as. My bet is that the problem on the MB and MBP is that it is listed as a MB or MBP. Apple is LIMITING the RAM on those configurations as it is NOT able to earn revenue so why support it. I believe when Apple's margin supports it, Apple will be offering 8 GB of memory. This has NOTHING to do with a hardware or software PROBLEM. This is Apple limiting it until it can benefit from selling that memory and officially stating that 8 GB is the maximum memory. I really think this is the only scenario that makes sense. And the "Boot Camp" BIOS emulation is also limiting this on the other side. Time will tell.

 

[commander.data]

Could you please tell me what does the system say about the computer under About this Mac? Go into more info, in System Profiler see what "Model Name" and "Model Identifier" are listed as. My bet is that the problem on the MB and MBP is that it is listed as a MB or MBP. Apple is LIMITING the RAM on those configurations as it is NOT able to earn revenue so why support it. I believe when Apple's margin supports it, Apple will be offering 8 GB of memory. This has NOTHING to do with a hardware or software PROBLEM. This is Apple limiting it until it can benefit from selling that memory and officially stating that 8 GB is the maximum memory. I really think this is the only scenario that makes sense. And the "Boot Camp" BIOS emulation is also limiting this on the other side. Time will tell.

Em. If he is using a P45 motherboard than he is not using a Mac, but running OS X on a non-Apple computer against the licensing policy. The P45 is a consumer desktop chipset which Apple has never used. All notebooks and the Mac Mini and iMac use mobile platforms and the Mac Pro uses a server/workstation platform.

 

[Scottsdale]

Wow. Please stop until you read for a few more hours.

EFI is essentially the bios.

Linux 64bit can be burned and booted in a few minutes and then we'll have our answer. Somebody just do it already, this is getting ridiculous.

I am willing to go say $5 with you that I am right on this. I believe Apple does not want 8 GB running until Apple can earn a slice of the revenue from selling it as an option. There should be a mighty fine "margin" in selling 8 GB of memory. MORE importantly, Apple could want it as another reason for people to make the switch and buy the new MBP. Furthermore, it may make ALL MB owners upset but Apple will probably further differentiate the Pro line by only offering it on the MBP at least for a while. My guess is Apple has also ensured the BIOS emulation will NOT allow 8 GB running on the other side ALSO.

I agree I am no expert, but this makes PERFECT sense.

 

[iBookG4user]

I find it rather odd that if the MacBook pro cannot use the remaining 4GB, why isn't it writing to the hard disk and showing that via Page Outs?

 

[Fukui]

Hmm, has anyone thought that maybe all the crashing was caused by faulty ram??
Its happened before (its happened to me).

Maybe they should swap out those 4GB chips for another new pair and see what happens. If there were a bad bit in there somewhere, then that would explain the consistent crashing when it reaches a certain memory load.

 

[Cave Man]

Hmm, has anyone thought that maybe all the crashing was caused by faulty ram?? Maybe they should swap out those 4GB chips for another new pair and see what happens.

Three of us have independently tried this (8 gb) with the same result, thus it is unlikely that faulty RAM is the culprit.

 

[Fukui]

Three of us have independently tried this (8 gb) with the same result, thus it is unlikely that faulty RAM is the culprit.

I see. Well, lets hope its something easily fixed maybe a firmware update...
I'm happy at least I can get 6GB in my MBPro...

 

[emsolutions]

64 Bit Architecture

Interesting note on Intel's Web site regarding Intel Core 2 Duo 64 Bit Architecture:

Could that be the reason why it is not working ?

"Intel® 64 architecture delivers 64-bit computing on server, workstation, desktop and mobile platforms when combined with supporting software.¹ Intel 64 architecture improves performance by allowing systems to address more than 4 GB of both virtual and physical memory."