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Macbook Pros: 64bit?

There is a difference between the chipset and the CPU. The CPU is 64-bit. It seems the chipset is 32-bit. The means that you can only have 4Gb of RAM, but you can run 64-bit software.
 
robbieduncan said:
There is a difference between the chipset and the CPU. The CPU is 64-bit. It seems the chipset is 32-bit. The means that you can only have 4Gb of RAM, but you can run 64-bit software.
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Alright, thanks for clarifying that.

So...what does that mean when Snow Leopard comes out? Will we still see the same performance boost of going all 64-bit by still having a 32-bit chipset?

Tex-Twil said:
This picture here is kind of scarry : http://static4.ifixit.com/igi/ibNAinnlQ5XKQXpH.large

It looks like the new MBP is MUCH larger that the early 2008 model :eek:
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Haha, I do believe that's some good ol' eye-trickery there. In reality (at least, according to Apple), it's not significantly larger. A quarter inch wider, a little bit deeper, but 0.05" thinner!
 
nephilim7 said:
this is incorrect.
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In what way? If the chipset (the NVidia 9400M combined north/south bridge and GPU) has a 32-bit memory controller then you will be limited to 4Gb of RAM. The CPU and OS should still be able to run in 64-bit mode: the MMU will be translating addresses from VM, per-process space to actual physical RAM space anyway.

Firanide said:
Alright, thanks for clarifying that.

So...what does that mean when Snow Leopard comes out? Will we still see the same performance boost of going all 64-bit by still having a 32-bit chipset?
Click to expand...

What performance boost? There is nothing intricately faster about 64-bit. Sure you get a few extra registers on the CPU but that's not going to make a huge difference. Unless the process can use more than 4Gb of address space it gains very little by being 64-bit...
 
robbieduncan said:
In what way? If the chipset (the NVidia 9400M combined north/south bridge and GPU) has a 32-bit memory controller then you will be limited to 4Gb of RAM. The CPU and OS should still be able to run in 64-bit mode: the MMU will be translating addresses from VM, per-process space to actual physical RAM space anyway.
Click to expand...

*if*

*should*

=/

no one would make a 32 bit memory controller now any more than they would release a 32 bit CPU. The last mbp to have a 32 bit controller was napa.

penryn runs 8g fine in linux. and 6g fine in OSX.
 
nephilim7 said:
penryn runs 8g fine in linux. and 6g fine in OSX.
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On an Intel chipset that has a >32bit memory controller. NVidia do not appear to have provided any details on the memory controller on their website (I checked). It says it's "128-bit" but this is the width of the data bus, not the address bus. So far only one site I have seen has said anything on this and they claim it's 32-bit. So there is evidence for this, whereas your claims that I am flat-out wrong are based on speculation...
 
robbieduncan said:
On an Intel chipset that has a >32bit memory controller. NVidia do not appear to have provided any details on the memory controller on their website (I checked). It says it's "128-bit" but this is the width of the data bus, not the address bus. So far only one site I have seen has said anything on this and they claim it's 32-bit. So there is evidence for this, whereas your claims that I am flat-out wrong are based on speculation...
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and you are saying you are flat out right based on speculation.

do you really think nvidia would make a 32 bit memory controller... after intel got beaten sideways for this 2 years ago? You need 64bit addressing to handle 4G with all the baggage of the x86 mess. unless you lie.. which is what some manufacturers did.
 
nephilim7 said:
and you are saying you are flat out right based on speculation.
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I disagree: I am basing my answers on a public stated declaration on a reasonably trusted site that is linked at the top of this thread.

I view this entire thread to be under the assumption that they are correct. If you disagree with this fact you should have quoted the original post/some text from that site and claimed they were wrong rather than attacking me where I said "It seems the chipset is 32-bit". At no point have I said 100% that the chipset it is 32-bit: I have always hedged my statements to show that I am working on the assumption that the article under discussion is correct. This is in direct contradiction to you; you have always claimed, flat-out, that it's >32-bit without any hedging of your language and no proof. I see little point in continuing this discussion...
 
robbieduncan said:
I disagree: I am basing my answers on a public stated declaration on a reasonably trusted site that is linked at the top of this thread.

I view this entire thread to be under the assumption that they are correct. If you disagree with this fact you should have quoted the original post/some text from that site and claimed they were wrong rather than attacking me where I said "It seems the chipset is 32-bit". At no point have I said 100% that the chipset it is 32-bit: I have always hedged my statements to show that I am working on the assumption that the article under discussion is correct. This is in direct contradiction to you; you have always claimed, flat-out, that it's >32-bit without any hedging of your language and no proof. I see little point in continuing this discussion...
Click to expand...

ifixit's statements are wrong. They say something about 'they are sticking to 32 bit chipsets in their notebook line so you are stuck with 4G' which was true a few years ago, but is not true about early 2008.

This does not say that the current chipsets (late 2008) are not capable or are capable.. voting on a rabbits sex doesn't do anything but annoy the rabbit. Apple knows that penryn mbps can support 8G in 10.6.. they have to know this, they designed the things. Would they then, as they redesign their entire line choose to limit it to 4G? Perhaps.. but I think it's unlikely.

This isn't an attack, it's another opinion.

also properly written video filters, DSP and things like rendermans prman running RSL get a fairly significant speed boost in 64 bit. Not exactly pedestrian stuff, but you're not supposed to be doing pedestrian stuff on a macbook pro.
 
nephilim7 said:
ifixit's statements are wrong. They say something about 'they are sticking to 32 bit chipsets in their notebook line so you are stuck with 4G' which was true a few years ago, but is not true about early 2008.

This does not say that the current chipsets (late 2008) are not capable or are capable.. voting on a rabbits sex doesn't do anything but annoy the rabbit. Apple knows that penryn mbps can support 8G in 10.6.. they have to know this, they designed the things. Would they then, as they redesign their entire line choose to limit it to 4G? Perhaps.. but I think it's unlikely.

This isn't an attack, it's another opinion.

also properly written video filters, DSP and things like rendermans prman running RSL get a fairly significant speed boost in 64 bit. Not exactly pedestrian stuff, but you're not supposed to be doing pedestrian stuff on a macbook pro.
Click to expand...

can you please back up your claims with links or something? so far you are just saying they are wrong where there is an article in this page saying the opposite. not gonna lie, but im taking the articals word for it atm
 
robbieduncan said:
I disagree: I am basing my answers on a public stated declaration on a reasonably trusted site that is linked at the top of this thread.

I view this entire thread to be under the assumption that they are correct. If you disagree with this fact you should have quoted the original post/some text from that site and claimed they were wrong rather than attacking me where I said "It seems the chipset is 32-bit". At no point have I said 100% that the chipset it is 32-bit: I have always hedged my statements to show that I am working on the assumption that the article under discussion is correct. This is in direct contradiction to you; you have always claimed, flat-out, that it's >32-bit without any hedging of your language and no proof. I see little point in continuing this discussion...
Click to expand...

I wonder where did iFixit got this information? If they have MCP79 datasheet, it'd be nice if they told us so. As of now there's no information publicly available about this chip... I think previous motherboards from NVIDIA used HyperTransport, which operates differently than usual FSB? I don't know much about it though, and it's generally hard to find reliable information about anything NVIDIA-related.

Anyway, nForce 7xx series apparently supported up to 8GB RAM with Intel CPUs (although this is taken from Wikipedia, so...), and MCP7A is supposedly next version of it, and since MCP79 is the mobile version of MCP7A... I simply find it hard to believe that NVIDIA would downgrade its chips and Apple would use them so close to Snow Leopard's release. Then again, they did insist Santa Rosa MBP can't use more than 4GB RAM, even though they seem to work flawlessly with 6GB (though have issues with 8GB).
 
dukebound85 said:
can you please back up your claims with links or something? so far you are just saying they are wrong where there is an article in this page saying the opposite. not gonna lie, but im taking the articals word for it atm
Click to expand...

logic and reason don't rely on convincing you or anyone on anything. You have the information to make your own call available to you.

My claim that the early 2008s can support more than 4G and actually use it, is substantiated in this monster thread...

https://forums.macrumors.com/threads/573906/

ifixit said that 'apple is still using 32 bit memory controllers', this is incorrect, and leads me to believe they don't really know.
 
aleksandra. said:
I wonder where did iFixit got this information? If they have MCP79 datasheet, it'd be nice if they told us so. As of now there's no information publicly available about this chip... I think previous motherboards from NVIDIA used HyperTransport, which operates differently than usual FSB? I don't know much about it though, and it's generally hard to find reliable information about anything NVIDIA-related.

Anyway, nForce 7xx series apparently supported up to 8GB RAM with Intel CPUs (although this is taken from Wikipedia, so...), and MCP7A is supposedly next version of it, and since MCP79 is the mobile version of MCP7A... I simply find it hard to believe that NVIDIA would downgrade its chips and Apple would use them so close to Snow Leopard's release. Then again, they did insist Santa Rosa MBP can't use more than 4GB RAM, even though they seem to work flawlessly with 6GB (though have issues with 8GB).
Click to expand...

There was a time when intel was getting a lot of flack about the memory controller issues, I can see how someone that hasn't been keeping up with intels mobile line would make the mistake of assuming that it is still the case.
 
There is an obvious way to test this: if one of the numerous people with these new machines could just try it with more than 4Gb of RAM...

Personally I'd be very happy if they support more. Whilst I'm not in the market right now I find the 2Gb hard limit of my MBP very annoying and when I replace it I'd certainly want more than 4Gb.
 
robbieduncan said:
There is an obvious way to test this: if one of the numerous people with these new machines could just try it with more than 4Gb of RAM...

Personally I'd be very happy if they support more. Whilst I'm not in the market right now I find the 2Gb hard limit of my MBP very annoying and when I replace it I'd certainly want more than 4Gb.
Click to expand...

hmm after reading that thread over (I had a lot of participation in the testing) I noticed that I made a mistake in saying 8G is confirmed working in snow leopard. It was 6G that worked in snow leopard, and 6G works in 10.5 as well.

I don't have snow leopard to test with, I have 8G and it runs fine in linux, but linux isn't doing a lot of wacky PAE shifting which leopards kernel seems to be doing, which could account for the 8G/6G mess.

also as a note to future readers, if you have a new machine and access to either 6g or 8g of memory I encourage you to check out the thread linked above and run the app that is on around page 4? It allocates and actually uses 1 gig of memory per instance and is an easy way to test your machine.
 
robbieduncan said:
There is an obvious way to test this: if one of the numerous people with these new machines could just try it with more than 4Gb of RAM...

Personally I'd be very happy if they support more. Whilst I'm not in the market right now I find the 2Gb hard limit of my MBP very annoying and when I replace it I'd certainly want more than 4Gb.
Click to expand...

though it would surprise me if apple made nvidia take a step backwards, secretly I hope it as it would increase the value of my penryn... though that begs the question of what mbp would I replace it with?
 
I don't know where iFixit and AnandTech get their information, but according to the comparison from here: http://www.anandtech.com/mb/showdoc.aspx?i=3432 it is (chip - memory controller):

AMD 780G - N/A
Intel G45 - 2 x 64-bit DDR2/DDR3 channels
NVIDIA GeForce 9400 - 2 x 64-bit DDR2/DDR3 channels
NVIDIA GeForce 9300 - 2 x 64-bit DDR2/DDR3 channels
NVIDIA GeForce 8200 - N/A

These are desktop motherboards, but it should be similar for mobile version.
 
aleksandra. said:
I don't know where iFixit and AnandTech get their information, but according to the comparison from here: http://www.anandtech.com/mb/showdoc.aspx?i=3432 it is (chip - memory controller):

AMD 780G - N/A
Intel G45 - 2 x 64-bit DDR2/DDR3 channels
NVIDIA GeForce 9400 - 2 x 64-bit DDR2/DDR3 channels
NVIDIA GeForce 9300 - 2 x 64-bit DDR2/DDR3 channels
NVIDIA GeForce 8200 - N/A

These are desktop motherboards, but it should be similar for mobile version.
Click to expand...

That refers to the data bus, not the address bus. 2x64=128-bit as stated by NVidia on their specs page. Even my distinctly 32-bit CD MBP uses 64-bit memory in this sense...
 
I rang apple to finally find the true answer...

They took my number and are going to ring me back :) will post what they say!
 
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