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So does the new MBP support more than 4gb - officialy
- Thread starter chefwong
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The MBP (new or old) does not officially support more than 4 GB of RAM. Here's the User's Manual for the new MBP. Jump to page 42 and you'll see that it says "You can add two 2 GB memory modules for a maximum of 4 GB of memory."
Unofficially though, it's a different story. People on this forum have successfully installed 8 GB of RAM on the early 2008 MBP, and I assume that the same can be done with the late 2008 models.
Unofficially though, it's a different story. People on this forum have successfully installed 8 GB of RAM on the early 2008 MBP, and I assume that the same can be done with the late 2008 models.
Actually, I believe the chipset officially (according to Nvidia) DOES support 8GB, but it isn't mentioned for the MBP due to the lack of 4GB DDR3 SO-DIMMs. There was a post a few days ago when someone said they got an Apple rep to confirm that was the case.
The Late 2008 MB still use 32bit architecture, technically they can only access 4gb ram.
Interesting, I was not aware of that. Are there any links, is there any proof? I saw another thread with both similar and divergent claims.
By the way, awesome screenname
Wouldn't 8 gigs create a lot of heat?
On a side note, did you ever beat the last lvl on Advanced? Man I couldn't figure it out.
Right... 32-bit chipset means no... Not officially. But, can they use PAE (Physical Address Extension)? That is what older WinTel boxes use with Server 2003 Enterprise. It is not the most efficient way to go, but it is possible this way...
Interesting, I was not aware of that. Are there any links, is there any proof? I saw another thread with both similar and divergent claims.
By the way, awesome screenname
http://www.appleinsider.com/article...bits_santa_rosa_and_the_great_pc_swindle.html
The Nvidia chipset MUST be a 64-bit chipset. If it wasn't, we should have heard complaints by now from new MBP owners with 4GB installed but only 3.5GB showing up in System Info.
32bits gives you 4GB of address space, but addresses are used for more than just physical RAM. Installing 4GB of RAM into a 32bit system will give you about 3.2-3.5GB of usable RAM. Back when they used 32bit chipsets, Apple only supported 3GB max installed RAM (since the 4th GB would be mostly wasted). Since Apple is shipping the new MBPs with 4GB as a supported configuration, the Nvidia chipset must support 4GB physical ram, thus making it a 64bit chipset.
However, it's also possible that the Nvidia chipset isn't compatible with >2GB DDR3 SODIMMs, so 4GB might be the max. We won't know for sure until 4GB DDR3 SODIMMs hit the market and someone can test them.
32bits gives you 4GB of address space, but addresses are used for more than just physical RAM. Installing 4GB of RAM into a 32bit system will give you about 3.2-3.5GB of usable RAM. Back when they used 32bit chipsets, Apple only supported 3GB max installed RAM (since the 4th GB would be mostly wasted). Since Apple is shipping the new MBPs with 4GB as a supported configuration, the Nvidia chipset must support 4GB physical ram, thus making it a 64bit chipset.
However, it's also possible that the Nvidia chipset isn't compatible with >2GB DDR3 SODIMMs, so 4GB might be the max. We won't know for sure until 4GB DDR3 SODIMMs hit the market and someone can test them.
3.5GB show of 4GB installed RAM is a Memory Mapped I/O issue. 32 Bit chipsets with 4GB RAM installed show as 4GB in OSX environment. After Santa Rosa, all Intel chipsets ( as well as 3rd party chipset manufacturers ) moved MMIO out of System RAM.
However Windows still does include MMIO to the system RAM
So, nVidia 9400M could and probably is a 32bit Chipset.
Ok, ok, no need to roll your eyes. That doesn't mention the newest NVidia laptops or chipsets at all, just that "For example, Apple's 64-bit Core 2 Duo laptops prior to the second half of 2007 all used 32-bit addressing." Since the article was written this year, wouldn't that imply that newer Apple laptops use 64-bit adressing?
Thanks for the link though.
When Apple were using 32 bit chipsets before, they quoted 3GB as the maximum supported RAM. In other words they were not going to sell you 4GB when the machine could not use more than 3.2 or thereabouts, even though you could put 4GB of 3rd party RAM in and have it show up in the System Profiler.
I would like to see some definite proof, but I find it hard to believe they would go back from a 64 bit chipset to a 32 bit one, and even if they did, having no qualms about selling you 4GB even though you couldn't use it all.
You're wrong. Intel moved MMIO out of system RAM with the introduction of Santa Rosa, that's why you saw 3GB limit on earlier Macbooks.
nVidia's new 9400M moves the MMIO also out of system RAM, using all 4GB whenever necessary. PAE is another solution, but since it's developed by Intel, I don't see nvidia chip supporting more than 4GB.
You're automatically assuming that show of 4GB RAM in system profile indicates 64bit chipset, but it very well could be a 32 bit chipset with MMIO storage removed from system RAM.
No I didn't say that. The pre Santa Rosa Macbook shows 4GB even though it has a 32 bit chip set.
But are you saying Apple have moved back from a 64 bit chipset to a 32 bit one, and whereas previous MBPs are running quite well with 6GB RAM, this will not be possible on the new models?
No, I'm saying that Apple never used a 64bit chipset on it's notebook line. Pre Santa Rosa notebooks show 3GB of RAM when 4GB is installed.
6GB show of MBP could very well be with PAE, which is an Intel tech. nVidia's new chipset may or may not have it.
So you are saying that Santa Rosa is a 32 bit chipset as well then? While it solves the MMIO issue, you still could not then run a single process >4GB on a machine with that chipset?
PAE is unnecessary.
PAE is only for accessing more than 4 GB of RAM on a 32-bit system. Core 2 Duo is 64-bit. Therefore unless nVidia were idiots, their chipset can natively support more than 4 GB of RAM in pure 64-bit mode. No PAE needed. (And since Leopard is fully 64-bit native on Intel chips; the OS can take full advantage, too.)
Intel crippled the "Santa Rosa" platform by disabling 64-bit memory mode in the PM965 chipset, which limited it to 4 GB of RAM (doesn't even have PAE, much less native 64-bit.) Their "Montevina" platform (with the PM45 chipset,) does support native 64-bit mode; and supports 8 GB of RAM maximum.
I would hope that nVidia's chipset matches this, but I can't find many details on the 'chipset' side of the 9400M, just the GPU side. (Other than the most basic "supports Core 2 Duo, 1066 MHz FSB, number of USB ports, etc.)
PAE is only for accessing more than 4 GB of RAM on a 32-bit system. Core 2 Duo is 64-bit. Therefore unless nVidia were idiots, their chipset can natively support more than 4 GB of RAM in pure 64-bit mode. No PAE needed. (And since Leopard is fully 64-bit native on Intel chips; the OS can take full advantage, too.)
Intel crippled the "Santa Rosa" platform by disabling 64-bit memory mode in the PM965 chipset, which limited it to 4 GB of RAM (doesn't even have PAE, much less native 64-bit.) Their "Montevina" platform (with the PM45 chipset,) does support native 64-bit mode; and supports 8 GB of RAM maximum.
I would hope that nVidia's chipset matches this, but I can't find many details on the 'chipset' side of the 9400M, just the GPU side. (Other than the most basic "supports Core 2 Duo, 1066 MHz FSB, number of USB ports, etc.)
I remember some literature on Santa Rosa supporting 8 GB of RAM. Sadly I can't find it anymore and Intel's own datasheets say 4 GB of RAM.
How do you explain 6 and 8 GB on older MacBooks then?
I put dual 4GB modules in an "early 2008" MacBook Pro. It saw all 8 GB according to Activity Monitor but it ran really slow -- like it was confused -- especially when I ran Compressor with 2 instances or After Effects in Multiprocessing mode (which spawns two sub-process that use 3GB each).
I went back to dual 2GB modules and it ran at normal speed again.
I'll be trying it again with the "late 2008" MacBook Pro. One of the memory makers is sending me samples. I'll report back.
I went back to dual 2GB modules and it ran at normal speed again.
I'll be trying it again with the "late 2008" MacBook Pro. One of the memory makers is sending me samples. I'll report back.