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    Laptops without 3327MB RAM cap?

    Discussion in 'Hardware Components and Aftermarket Upgrades' started by sloc, Feb 20, 2008.

  1. sloc

    sloc Newbie

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    Does anyone own a laptop with 4GB RAM installed and is running with ~4096MB RAM available? My Dell E1505 running T7200 C2D 64bit Vista can only get ~3327MB as it is limited by the 945PM chipset (no memory remapping). Does the Santa Rosa PM965 chipset allow full 4096MB RAM usage? What about the AMD chipsets and laptops?

    Thanks in advance.
     
    sloc, Feb 20, 2008
    #1
  2. Tinderbox (UK)

    Tinderbox (UK) BAKED BEAN KING

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    Hi.

    cpu-z 1.44

    Northbridge Intel GM965 rev. C0
    Southbridge Intel 82801HBM (ICH8-ME) rev. 03
    Graphic Interface PCI-Express
    PCI-E Link Width x16
    PCI-E Max Link Width x16
    Memory Type DDR2
    Memory Size 4096 MBytes
    Channels Dual (Symmetric)
    Memory Frequency 332.5 MHz (3:5)
    CAS# 5.0
    RAS# to CAS# 5
    RAS# Precharge 5
    Cycle Time (tRAS) 15

    but i only have 3.3gb avaliable in Vista x32

    regards

    John.
     
    Tinderbox (UK), Feb 20, 2008
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  3. AlexF

    AlexF Notebook Deity

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    You need a 64-bit OS (Vista x64) and a chipset with a memory controller and BIOS that supports memory remapping (ie: 965 and up).

    There was talk about maxxing it out:

    http://forum.notebookreview.com/archive/index.php/t-179641.html

    AMDs have the memory controller built into the CPU but are still subject to the OS requirement.

    Basically, a 32-bit OS won't be able to work with the full 4 GB because a) they don't see more than 4 GB, and b) your system devices use the memory "space" between the 3-4GB mark. Since your physical memory overlaps with this reserved space, you lose access to it. Remapping would allow you to regain use of that space.

    Edit: http://support.microsoft.com/default.aspx/kb/929605
     
    AlexF, Feb 20, 2008
    #3