Powerbook + New memory = Heat?

Discussion in 'Macintosh Computers' started by vsp, Feb 19, 2005.

  1. vsp macrumors regular

    Jan 23, 2004
    Chico, Ca
    Having just resolved heat/fan issues on my 15 in, 1.25 PB I'm very aware of the temperature of the computer.

    Just yesterday I installed 2 sticks of 512 MB memory, replacing the two 256 MB sticks the book came with. The memory was purchased from Small Dog and appears to be the correct memory (though, surprising to me, the actual sticks were smaller in width--length was the same).

    The machine is snappier and I'm quite happy with the switch, but it now runs a few degrees hotter. Not really a problem but when I play games the fan comes on early and stays on. It used to come on occasionally, and only for a few minutes.

    Is this normal behavior? I would think that Small Dog would sell memory that's within specs, but I don't know if adding more memory would up the internal heat.

    If this is abnormal, I'm returning the memory and trying a different company. If this is to be expected than all is well. I'm currently researching laptop stands and coolpads to buy.
  2. CanadaRAM macrumors G5


    Oct 11, 2004
    On the Left Coast - Victoria BC Canada
    More memory = more heat, simply because there are more transistors wasting more milliwatts.

    Now, there are two designs for the memory chips that are used on SODIMMs; TSOP and MBGA.

    TSOP is what you think of when someone says "computer chip" = they are rectangular, about 3/8" x 3/4" (10mm x 20mm)

    MBGA are flatter and smaller, about 3/8" (10mm) square wth no visible connectors.

    MBGA chips are smaller and more energy efficient, so modules made with the "should" run cooler. The up to date designs of 512 Mb and 1 Gb SODIMMs use MBGA chips. Some of the "bargain" PC generic SODIMM modules out there still use TSOP.

  3. vsp thread starter macrumors regular

    Jan 23, 2004
    Chico, Ca
    So if I understand correctly, if my old RAM and my new RAM have the same type of chips on them I can expect my upgrade to run a few degrees hotter simply because more work is being done.

    Or, if the new RAM is using TSOP it may be running hotter simply because it isn't as energy efficient. I'll check on that. If they are TSOP I'll likely return them and look around for MBGA chips, even if it's a bit more expensive.

    Thanks for the info.

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