Installed 2x512MB RAM into G5 1.6GHz but only shows as 2x256MB

Discussion in 'PowerPC Macs' started by ToTo Man, Oct 22, 2008.

  1. macrumors regular

    Oct 22, 2008
    Hi. This is my first post. I've owned a G5 1.6GHz PowerMac used since 2005. It came equipped with 256MB RAM (2x128MB PC2700 DDR 333 CL2.5v). Shortly after I purchased an additional 512MB RAM (2x256MB Kingston G5400 PC3200 CL2.6v), which has worked perfectly ever since. I have just purchased an additional 1GB of RAM (2x512MB Kingston G5400 PC3200 CL2.6v) to replace the 2x128MB strips, thus increasing my total RAM from 768MB to 1.5GB. I installed it today and was puzzled to find the System Profiler is displaying 4x256MB instead of 2x512MB and 2x256MB. In other words it is recognising the new RAM but only 50% of its capacity. Is this a common problem, and is there a remedy available? Thanks in advance for any comments. :)
  2. macrumors 65816


    May 20, 2008
    The ram isn't supported. Check with CanadaRam for the right ram to purchase.
  3. thread starter macrumors regular

    Oct 22, 2008
  4. macrumors 68020


    Jun 14, 2008
    New Hampshire
    To see the modules specified for that model on the OWC site that many of us rely on, see OWC G5 1.6MHZ Memory. This doesn't really help your problem, but will confirm the correct RAM for your Mac anyway. :( And BTW- the Apple spec is for PC2700 or faster- PC3200 will step down to operate at PC2700 speed though, which is why almost all of the OWC modules are PC3200.
  5. macrumors regular

    Oct 11, 2008
    High density ram does not work either.
  6. thread starter macrumors regular

    Oct 22, 2008
    The G5400/512 strips are single sided and has the same number of chips as my G5400/256 (8 chips). Does this imply that the 512 strips are high density? I've not seen RAM for my G5 that has chips on both sides.
  7. macrumors regular

    Oct 11, 2008
    It depends on the manufacturer. Start putting numbers you see on the chips and labels into google and eventually you'll find a site that says high or low density.

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