MacBookPro

etto72etto72
Posted:
in Future Apple Hardware edited January 2014
Like many of you i also can't wait for the coming 17" MBP(hopefully in spring!)

There is one thing i would like to ask about the currently MBP 15"model,why is the RAM memory extension only up to 2G?? should a pro notebook get at list to 4G like IBM or ACER?

Any possibility that the 17"MBP will have bigger extendibility?

Thanks to all

Ettore

Comments

  • Reply 1 of 4
    thttht Posts: 5,443member
    Two things limit the amount of memory that can be placed into Apple's laptops. The primary one for the longest time is the fact that laptops are space constrained and the typical maximum amount of memory slots that can placed into them is 2 slots in the form of these small form factor memory modules called SO-DIMMs. The maximum amount that can typically be place on these SO-DIMMs has been 1 GB. So, 2 GB is about the maximum amount of memory that can practically be placed into a laptop.



    The second one that will be a problem going into the future, when 2 GB SO-DIMM modules are available, is that most laptops are 32 bit memory systems that can only use a theoretical maximum of 4 GB of main memory. In reality, they can only physically use about 2.5 GB of main memory.



    If you want a laptop capable of expanding to 4 GB, an AMD Turion64 system is pretty much it (unless you want a SPARC laptop), pending the availability of 2 GB SO-DIMMs. By that time, Apple and virtually all other vendors will likely be shipping laptops with 64 bit memory systems capable of using over 4 GB though.



    One other thing is that a 2 GB memory module in the future may in fact not use the existing SO-DIMM form factor and therefore is incompatible with all old systems. So, we may not even have an option.
  • Reply 2 of 4
    atomichamatomicham Posts: 185member
    Quote:

    Originally posted by THT

    The second one that will be a problem going into the future, when 2 GB SO-DIMM modules are available, is that most laptops are 32 bit memory systems that can only use a theoretical maximum of 4 GB of main memory. In reality, they can only physically use about 2.5 GB of main memory.



    Intel (and AMD) have the PAE (Physical Address Extensions) which extend the addressable memory beyond 32-bit. For the Pentium line, it was 36-bit IIRC (which would give ~68GB of space). I have NO idea if any of that was included in the Core chipset or even if Apple has written the kernel to handle it. I don't think it was widely used outside of linux kernels enabled for PAE.
  • Reply 3 of 4
    thttht Posts: 5,443member
    No need to get pedantic about PAE when talking about laptop systems. Heck, the newly minted Sossaman only has 2 DIMM slots and it's used in servers.
  • Reply 4 of 4
    smalmsmalm Posts: 677member
    Calistoga, the chipset for Yonah, can only address 2GB on a 667MHz memory bus and it supports 4GB on a 533MHz bus. But as THT already said there are no 2GB SO-DIMMs.



    So the 4GB from Acer and Lenovo can't be considered as lies but they don't tell you the whole truth as you cannot buy a 4GB model from them and WinXP can't address the whole 4GB when the 2GB SO-DIMMS finally become available.



    THT, I seem to remember the barrier at 3.5GB? 2.5GB sounds very ugly!

    Sossaman can address 16GB in PAE mode using the E7520 chipset.
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