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

[Berlepsch]

I suspect that the Macbook, 8GB and Leopard are working just fine, as it reports the correct amount of memory. For Apple to "cheat" here could lead to all sorts of trouble with programs that query the amount of free memory.

It is quite plausible that Parallels is simply confined to the lower 4GB, because the guest OSs have a limited direct hardware access using Intel's VT mechanism. Since Parallels emulates a 32 bit processor, I expect that this reduces the memory range it can use to the lower 4GB.

Someone should check the memory usage of the Macbook with some 64 bit applications to give more reliable results.

 

[drachir24]

when i use 4+2 can i use DDR3 with same good result?And second question is 4+2 means i lose dual channel dual mode.Can i buy 3+3.Thanks

 

[Scottsdale]

Quit Saying It's Leopard!

This has NOTHING to do with Leopard. Why, because Leopard is running up to 32 GB of Memory on the Mac Pros.

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.

So, I am ONLY speculating here.

Why is it when I installed my Leopard retail disk it installed fine on my v 2,2 MBP with ALL drivers and etc and recognized it all fine. Did OS X recognize that I was installing it on a MBP? I go into the System Profiler and find ALL of the information about my MBP because OS X knows that it is a MBP. I did NOT tell OS X Leopard that I was installing this on a MBP. Now, is MBP coded, OK this is a MB, this is a MBP, this is a Mac Pro, this is a Mac Mini and giving coding instructions that interfaces and works AND KNOWS with WHICH hardware like EFI and ALL Apple imposed tolerances?

My guess, SINCE UP TO 32 GB, WORKS FINE on a Mac Pro that we are simply dealing with the OS X saying that it is a MBP and only x GB of Ram should work. Now, this would surely allow someone to Boot Camp and install a 64-bit version of Windows or Ubuntu and should OR NOT see 8GB.

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.

I would bet about nothing that this is NOT a hardware issue rather a software, OS X, not wanting to work with more than 4 GB because it is programmed to NOT to work because Apple says NO to more than 4 GB.

Come on this has nothing to do with hardware, possibly a firmware upgrade but lets remember WHY that would be necessary. Nothing to do with the capabilities of the actual Intel chip or the Nvidia GPU. BUT rather Apple's Motherboard Not allowing it until Apple gives the thumbs up and says ok Motherboard go ahead. Ok OS X, GO AHEAD. Let these guys install up to 8 GB of memory now. BTW, why wouldn't Apple want to sell us this memory at a PREMIUM?

Ok, everyone want to rip into me? I don't care. I just KNOW that UP TO 32 GB works on a Mac Pro so people saying that it's Leopard NOT SUPPORTING more than 4 GB are making NO SENSE to me.

BTW, I just bought the MB. I wanted the MBP, but I thought I would give it some time to see what processors they are running in a year. Also, hopefully, we will have Snow Leopard by then. Also, 8 GB of memory, OR MORE, may be less than a couple hundred bucks by then. More, YES MORE MEMORY. Remember, Intel is upgrading its processors next year to Nehalem. And, what about Quad processors? By then, probably running both graphics. By next August/September I expect the MBP will live up to OUR expectations of what the MacBook Pro SHOULD be. It currently is NOT. But the design and hardware is amazing. It is so much nicer than my v 2,2 MBP. I cannot wait to see how this evolves. It should be fun to login to MacRumors.com for the next year. Always wanting to see the next POSITIVE news about OS X and the new MBP.

Now start ripping so I can go find my couch and get off this computer long enough to watch a game or two this weekend.

Cannot wait to see the 8 GB of RAM working for ALL of our sakes. And IT WILL WORK, eventually.

Cheers to you all. Have a nice weekend.

 

[esquire360]

iFixit, can u 64-bit unbuntu for us? That would slve this!

Also

Where can I get 4gb sodimms ddr3?

 

[Hattig]

Its a HARDWARE LIMITATION.

OS X is 64 bit.

SNOW LEOPARD WONT FIX ANYTHING BECAUSE ITS A HARDWARE LIMITATION.

Leopard is a 32 bit kernel with PAE (allows for a strange segmented view of a larger address space (64GB) than a bog standard 32 bit system (4GB) but at the cost of having every memory access having to go via PAE (for the address remapping) which slows down the system.

Until Mac OS X gets a proper 64-bit kernel this problem will continue. Snow Leopard looks like being the one to sort this out.

Still, never mind eh, imagine all the people using Vista 32-bit on their 4GB PCs with 1GB graphics cards, and not knowing that they actually only have 2.3GB of usable memory.

 

[NintendoFan]

To everyone saying that Snow Leopard will save us, will you explain then how the Mac Pro works with more than 4GBs of RAM? Does it exhibit similar problems?

 

[Aqua lung]

Leopard is a 32 bit kernel with PAE (allows for a strange segmented view of a larger address space (64GB) than a bog standard 32 bit system (4GB) but at the cost of having every memory access having to go via PAE (for the address remapping) which slows down the system.

Until Mac OS X gets a proper 64-bit kernel this problem will continue. Snow Leopard looks like being the one to sort this out.

Still, never mind eh, imagine all the people using Vista 32-bit on their 4GB PCs with 1GB graphics cards, and not knowing that they actually only have 2.3GB of usable memory.

That's what I said in my earlier post, you would think people doing these tests would know better? especially coming from ifixit? I'm rather dissapinted about this...

OSX is still a 32bit OS with a 32bit kernel people, it uses PAE to address more ram, the Mac Pros have better PAE support compared to the notebook Chipset/Mobo and CPU.

 

[Maxintech]

Off the top of my head, something like this:

http://www.theshore.net/~caker/uml/patches/utils/eatmem.c

I had to comment out line 21 (#include <malloc.h>) to get it to compile on a mac...

Make sure developer tools are installed and compile with:

gcc eatmem.c -o eatmem

Then run (several times):

./eatmem 1G

Check activity monitor to be sure the "Real Memory" column is actually large... when finished, do a "killall eatmem" to free it up again. I tried this on a Mac Pro with 10GB RAM, and it will consume it all if you run enough instances.

If this test doesn't use all the ram on an 8GB laptop, then perhaps there's a problem. Until then, I'm not convinced.

You must compile in 64 bits to enable addressing more than 4GB in one process of eatmem program. To do this use the -m64 parameter for gcc

gcc eatmem.c -o eatmem -m64

To check your file use the command file like this:

file eatmem

The output is

$ file eatmem
eatmem: Mach-O 64-bit executable x86_64

In my iMac '07 with 4GB is the only way to allocate more than 3GB. If you run

./eatmem 4G

the Activity Monitor reports 3.16Gb in real mem column and in kind column reports Intel 64 bits; the only one process of this kind.

 

[Scottsdale]

not a problem.

As an additional statement/summary to my recent post; this is NOT a hardware problem nor is it a software problem. Leopard IS CURRENTLY supporting up to 32 GB memory on the Mac Pro. Our problem is someone at Apple does NOT want us to run 8 GB memory on the new/old MB or MBP YET.

Maybe Aple wants to be able to sell us this 8 GB RAM at a premium when the margin is acceptable to Apple.

Yes, I firmly believe this is it. And I believe Apple's OS X Leopard development team has coded this into Leopard via if hardware does not equal Mac Pro, then more than 8 GB RAM not addressable.

I, and my NON-developers, non-educated (in this field), brain am most certain.

I believe when Apple decides it should offer an 8 GB option, probably only as a MBP option, we will see it available in the Apple Store. Hopefully, Apple will view all past purchases as valid for the "update" even though Apple will probably NOT get that sale (benefit from the revenue, make the margin, and yes ADD to the ever growing BOTTOM LINE).

Let's all just hope that Apple is willing to switch the option "ON" for recent purchasers. I truly believe with ALL of my heart that this is the issue. It makes perfect sense given Apple's history and for the future benefits of switching and buying a NEW MacBook Pro. Further differentiating the "Pro" model and adding yet another benefit for the upgraded model to those who want or feel they need more RAM (a.k.a. RAM Hogs).

Please, pretty please Apple. Let us have our 8 GB RAM. If not, we shall start a petition for them to "enable it" thereby enabling us. No, it will not come to that.

Have a nice weekend.

 

[iMacmatician]

I haven't read the whole thread but…

Does anybody think that this is just a way to upsell people to the 17" MacBook Pro when it comes out with support for up to 8 GB RAM?

 

[Scottsdale]

please respect and appreciate ifixit

That's what I said in my earlier post, you would think people doing these tests would know better? especially coming from ifixit? I'm rather dissapinted about this...

OSX is still a 32bit OS with a 32bit kernel people, it uses PAE to address more ram, the Mac Pros have better PAE support compared to the notebook Chipset/Mobo and CPU.

I really believe you are WRONG for publicly bashing ifixit in their thread to HELP everyone get to the bottom of this. Not all enthusiasts are developers and programmers and they don't all know everything about something that isn't written out in a publication by Apple. Please reconsider and edit your post in courtesy of their ASSISTING with their time and money and not our money. They are trying to help. Give them a break.

Cheers.

 

[Aqua lung]

As an additional statement/summary to my recent post; this is NOT a hardware problem nor is it a software problem. Leopard IS CURRENTLY supporting up to 32 GB memory on the Mac Pro. Our problem is someone at Apple does NOT want us to run 8 GB memory on the new/old MB or MBP YET.

Maybe Aple wants to be able to sell us this 8 GB RAM at a premium when the margin is acceptable to Apple.

Yes, I firmly believe this is it. And I believe Apple's OS X Leopard development team has coded this into Leopard via if hardware does not equal Mac Pro, then more than 8 GB RAM not addressable.

I, and my NON-developers, non-educated (in this field), brain am most certain.

I believe when Apple decides it should offer an 8 GB option, probably only as a MBP option, we will see it available in the Apple Store. Hopefully, Apple will view all past purchases as valid for the "update" even though Apple will probably NOT get that sale (benefit from the revenue, make the margin, and yes ADD to the ever growing BOTTOM LINE).

Let's all just hope that Apple is willing to switch the option "ON" for recent purchasers. I truly believe with ALL of my heart that this is the issue. It makes perfect sense given Apple's history and for the future benefits of switching and buying a NEW MacBook Pro. Further differentiating the "Pro" model and adding yet another benefit for the upgraded model to those who want or feel they need more RAM (a.k.a. RAM Hogs).

Please, pretty please Apple. Let us have our 8 GB RAM. If not, we shall start a petition for them to "enable it" thereby enabling us. No, it will not come to that.

Have a nice weekend.

Does anybody think that this is just a way to upsell people to the 17" MacBook Pro when it comes out with support for up to 8 GB RAM?

Please read my post and read up on PAE, OSX is not yet a TRUE 64bit OS. It uses PAE to access more than 4GB of physical ram and this depends on how well your hardware supports PAE, but this is not the solution, the solution can only come from a true 64bit kernel.

 

[rumplestiltskin]

I'll just wait...

Once the MacBook can accept 8GB of RAM (and use it), I'll buy one. For now, however, I'll stick with my 2007 MacBook because horsepower alone isn't enough of a reason to spend $1700 (MacBook+RAM+AppleCare).

Sorry, Steve; I'm not impressed with this little tap dance.

 

[Aqua lung]

I really believe you are WRONG for publicly bashing ifixit in their thread to HELP everyone get to the bottom of this. Not all enthusiasts are developers and programmers and they don't all know everything about something that isn't written out in a publication by Apple. Please reconsider and edit your post in courtesy of their ASSISTING with their time and money and not our money. They are trying to help. Give them a break.

Cheers.

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.

 

[wizard]

PAE addressing!

To everyone saying that Snow Leopard will save us, will you explain then how the Mac Pro works with more than 4GBs of RAM? Does it exhibit similar problems?

This has already been mentioned but the most likely reason is that they turn on and use PAE extensions. If the OS/X install on MBP does not install the extensions to use the facility it won't work right. Further all of the hardware has to support PAE.

The problem is we can't say with 100% accuracy that the issue is just software or just hardware. Yeah the chip set is said to support 8 GB but that doesn't mean it was implemented by Apple in a way to support 36 bit addressing.

In a nut shell this is why everyone is asking about 64 bit Linux. Install that and you should be able to determine if the hardware supports large memory systems. Frankly 64 bit Linux is the only stable 64 bit OS available to the average user. Another option would be a Linux kernel that supports PAE extensions for multiple 32 bit address spaces.

 

[Aqua lung]

See this http://images.macrumors.com/article/2008/10/24/170020-activity_monitor_parallels.jpg

I didn't do the testing myself, but both Parallels were set for 2GB of RAM. There was also some Photoshop testing which showed similar results.

If you suggest a better way to test, I can try to pass it along.

arn

Yes, you should use a true 64bit OS to test the ram, run Vista 64bit via bootcamp or a 64bit Linux OS, OSX Leopard does not have a 64bit kernel and uses PAE to address more than 4GB because of the 32bit limitation but this depends on how well the hardware supports PAE.

 

[gnasher729]

Please read my post and read up on PAE, OSX is not yet a TRUE 64bit OS. It uses PAE to access more than 4GB of physical ram and this depends on how well your hardware supports PAE, but this is not the solution, the solution can only come from a true 64bit kernel.

This is nonsense. Software running on MacOS X can be any mixture of 32 bit and 64 bit software. You use 64 bit software if you need to access more than 4 GB of data. The part of the operating system that allocates memory space to 32 and 64 bit applications doesn't have to be 64 bit code at all. It doesn't _use_ more than 4 GB of memory, it just tells the applications how much memory to use. Changing this to 64 bit code would have no advantage.

The problem with the MacBooks is this: There has to be code that detects which memory chips are physically plugged in. That code seems to be working correctly when two 4GB chips are plugged in; it detects correctly the presence of those two chips. Next, there have to be physical address lines in the chipset that allow addressing the memory. It looks like the MBP has physical address lines that allow using 8 GB worth of addresses. However, things like video hardware etc. also need to be addressed, and the chipset is not capable of using all of 8 GB of RAM plus video hardware. Next, the chipset has to be capable of mapping physical addresses to hardware. For example, if you have 2GB + 1GB chips, every physical memory address from zero to 2 GB would be sent to the first RAM chip, every physical memory address from 2 GB to 3 GB would be sent to the second RAM chip, and all addresses in some other range would be sent to the video hardware. There is the question how flexible this hardware is. It seems that on earlier Macs that couldn't use all of 4 GB of RAM, it was flexible enough to split 2 GB to the first RAM chip, 1 1/4 GB to the second RAM chip, and 3/4 GB to other hardware. Maybe the MBP chipset isn't that flexible, or the video hardware has been given a fixed memory address at 6 GB.

Now the point where things seem to go wrong: It is apparently possible to put more memory into a new MacBook Pro than can be used for RAM. Maybe the maximum that can be used is 6 GB. It looks like some code in the OS decides that any RAM chip can only be either used completely, or not used at all. And since the second 4 GB chip cannot be used completely, it isn't used at all. So with 4 GB + 4 GB the operating system gets two numbers: 8 GB RAM are physically present in the computer, and 4 GB RAM can be used by applications. From the evidence we have seen, with a 4 GB + 1 GB combination the operating system will see 5 GB physically present, and 5 GB can be used by applications.

The fact that 5 GB systems works fine proves that this has nothing to do with a 32 bit or 64 bit Kernel. If 32 bitness were the problem, then the OS wouldn't be able to handle 5 GB either, but it can. The problem is that 4 GB + 4 GB is not a supported configuration, isn't supported, probably hasn't been tested on the MacBook Pro, and isn't handled optimally with current software.

It is very likely that the firmware can be changed to use part of a RAM chip only; after all, it can do that on pure 32 bit systems, where 3 1/4 GB of RAM can be used, which is one complete 2 GB chip and 5/8ths of the second 2 GB chip. It will probably happen when 4 GB chips are more affordable.

 

[wizard]

More bad info!

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.

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.

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.

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

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.

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.

 

[Squuiid]

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

Overall, our testing showed that the system is unstable at 8 GB of RAM. Parallels takes forever to load, even when using < 4 GB of total memory. The OS doesn't seem to page out properly, but we didn't spend a lot of time trying to track this down.

We suspect that this testing implies a two things:
1) The hardware can handle a 4 GB chip without any problem
2) There are OS-level limitations with 8 GB RAM on these systems.

Luke Soules
iFixit Labs

The obvious question is, what about using Windows Vista x64?!

 

[Aqua lung]

This is nonsense. Software running on MacOS X can be any mixture of 32 bit and 64 bit software.

Which is why we need to see a test using linux 64bit or Vista 64bit to put an end to all the speculation.

 

[Thomas2006]

Please read my post and read up on PAE, OSX is not yet a TRUE 64bit OS. It uses PAE to access more than 4GB of physical ram and this depends on how well your hardware supports PAE, but this is not the solution, the solution can only come from a true 64bit kernel.

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.

 

[contractcooker]

In complete agreement

The "64-bit migration" that we (mainstream users) are starting to embark on is going to be ugly. I know that people want to hold on to compatibility and the like but I feel like a strong and decisive push is what we need from the major players. If Apple (and in particular MSFT) go to only 64-bit we will see everyone follow. Sure, it will be a gigantic mess for a year or maybe even two but I think that's a hell of a lot better than spreading it out over ten years. Plus once everything is running correctly on 64-bit it will be a while before we need to go to 128-bit computing (I can't even begin to fathom maxing out the RAM capabilities of a true 64-bit computer). I'm no engineer so my understanding of this concept is a little fuzzy. Hopefully my post contains no major gaffs.

tb

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.

 

[yetanotherdave]

Maybe someone could install the just released build of snow leopard on a new MBP with 8gb installed, if it works, end of argument, if it doesn't, speculation will continue to run rife...

 

[dmmcintyre3]

Last Gen MacBook Pro

it supported 6 gb ram so try that

 

[wizard]

Actually hoping for a complete 64 bit transition.

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.

As the title suggest I'm really hoping that Apple goes all out with 64 bit support in Snow Leopard. It is not just the PPC support that is the issue but a whole raft load of other issues.

Thankfully I believe, based on public comments, that part of the goal of Snow Leopard is to remove the cruft. That could have huge pay offs. If it is cobined with stripped out PPC support we could end up seeing a very lean OS. One that reduces it's memory foot print and sppeds things up.

Yeah it would be a big step but would setup Apple for a decade. For people in 32 bit or PPC land Apple could put 10.5.x into extended maintenance.