[DevNine]

New macbok pros • Memory up to 3GB! anyone know what sort of ram is optimal?

[Tuoder]

DDR2 667 Mhz SO-DIMMs. The lower the latency the better.

[DevNine]

thanks for the reply.crucial doesn't have it on their website yet as far as I can see. Is this the same as the previous Mac Book Pros?

15" comes with 1GB (single SO-DIMM) of PC2-5300 (667MH 667 MHz DDR2 SDRAM)
two SO-DIMM slots support up to 3GB

single 2gb modules are super expensive!

[Tuoder]

It is the same stuff as before as crucial does have it as of the last time I looked like a month ago.

[DevNine]

thanks for clarifing this.

[harrisjamieh]

I find it odd why it only supports 3GB and not 4. There is no hardware limitation of 4GB, or indeed there shouldnt be

[Tuoder]

Originally Posted by harrisjamieh 

I find it odd why it only supports 3GB and not 4. There is no hardware limitation of 4GB, or indeed there shouldnt be

They would probably ask something like $1500 dollars for it. Maybe they didn't want to option something that no one would buy? It seems like 3GB would be a rare option, especially considering the price.

[workerbee]

RAMJET has 2GB RAM sticks at $269 each, so it would not actually be prohibitively expensive (as long as you're not ordering through Apple that is). But since the 24" iMac has the same RAM specs, I fear there is actually something to this strange 3GB limit.

[Tuoder]

Originally Posted by workerbee 

RAMJET has 2GB RAM sticks at $269 each, so it would not actually be prohibitively expensive (as long as you're not ordering through Apple that is). But since the 24" iMac has the same RAM specs, I fear there is actually something to this strange 3GB limit.

I really doubt there is a 3GB limit. Apple just charges waaaaaaaaaay too much for RAM. These are 64-bit machines. I m willing to bet that they will take whatever density that is manufactured for the slot. The Core Duos from before, I suspect will have a limit of 4GB.

[firefly]

No, I think it's likely that - like the iMac - there is a fixed 3GB limit, because the upper 1GB addressing space is reserved for PCI etc. It's a limitation of 32-bit x86 architecture. What I'm guessing then is that although the Core2Duo is true 64-bit, Apple's choice of chipset may not be. Anyone care to clarify?

[Eriamjh]

Originally Posted by harrisjamieh 

I find it odd why it only supports 3GB and not 4. There is no hardware limitation of 4GB, or indeed there shouldnt be

It happens.

[Tuoder]

Originally Posted by firefly 

No, I think it's likely that - like the iMac - there is a fixed 3GB limit, because the upper 1GB addressing space is reserved for PCI etc. It's a limitation of 32-bit x86 architecture. What I'm guessing then is that although the Core2Duo is true 64-bit, Apple's choice of chipset may not be. Anyone care to clarify?

Apple's choice of chipset is Intel, if I am not mistaken.

[spacecadet610]

Actually RAMJET 2 gb sticks are $675 each. For $269 you 2 1 GB sticks. big difference

Originally Posted by workerbee 

RAMJET has 2GB RAM sticks at $269 each, so it would not actually be prohibitively expensive (as long as you're not ordering through Apple that is). But since the 24" iMac has the same RAM specs, I fear there is actually something to this strange 3GB limit.

[mduell]

The chipset is the same as the previous MBP, 945PM from Intel. 945PM supports up to 4GB RAM at 667Mhz, however their is some cruftyness due to the way PCIe addressing space is handled, so the maximum usable capacity is 2 or 3GB depending on firmware revision.

[workerbee]

Originally Posted by spacecadet610 

Actually RAMJET 2 gb sticks are $675 each. For $269 you 2 1 GB sticks. big difference

My bad, thanks for clearing that up. Suddenly (and unfortunately) Apple pricing doesn't look so outrageous anymore.

[Simon]

I posted this in the new MBP thread, but since the topic has come up again here, I'll double-post.

There's a lot of misinformation being spread about the 3GB RAM limit. Here are some facts:

• the 3GB RAM limit is not a physical limit, it's a chipset limitation
• you can insert 4 GB (2 x 2 GB) just like you can on any PC notebook using the same chipset
• if you actually install 4 GB you will notice that only <3.2 GB are available to the OS and apps
• Apple knows that and hence they don't offer more than 3GB upgrades because it's a plain waste of money
• PC manufacturers know it as well, but some don't seem to give a damn

To make it short, you can insert 4 GB if you want. But if you actually want to use the full 4 GB you will have to wait until Intel releases the Santa Rosa chipset in 2007.

Additional info and some good links in this post.