How much RAM can 64-bit use?

Hello,how much RAM can 64-bit use?
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  1. See this chart for Windows 7 memory limits -

    Microsoft Windows Outreach
  2. Quote:
    Hello,how much RAM can 64-bit use?

    The theoretical limit is some Exibytes, but the current address tables are set up to 128GB, depending on the version you have.
  3. also depends on the motherboard ur using. Most motherboards have a limit to how much ram they can detect and use.
  4. Here are the upper RAM limits for the different editions of Windows 7:

    * Starter: 8GB
    * Home Basic: 8GB
    * Home Premium: 16GB
    * Professional: 192GB
    * Enterprise: 192GB
    * Ultimate: 192GB

    These limits are similar to those for Vista editions, expect that Vista Enterprise and Vista Ultimate have had their upper limits raised from 128GB to 192GB.

    The one to look out for there is the 16GB limit on Home Premium. If you’re building a Core i7 system then it’s quite easy (if you have the cash!) to exceed this limit. As long as you’re aware of the limit and plan your OS accordingly you’ll be OK.
  5. Quote:
    Hello,how much RAM can 64-bit use?

    Like some of your responses, it depends on what version of Windows you have. I had Windows 7 Home Premium and it only used 16G of RAM Memory. I know, because I put in 32G and when I went to the properties of my computer it had 32G showing, but in parenthesis it had (16 usable). I upgraded to Windows 7 Ultimate and it can use 192G. I can't imagine EVER needing that much, but I had purchase 4 x 8G RAM stick and wanted to use them all. Unfortunately the store I purchased them from closed a couple days after I purchased them, so I was stuck. I also depends on what motherboard you have. I have worked on some older computers that only used a maximum of 512M, but they came with Windows XP Home premium. The windows 32-bit uses only 4G on the Home Premium version. I found that out by purchasing Windows 8 32/64-bit and mistakenly downloaded the 32-bit. I had 16G in that computer and it was showing only 4 usable. I guickly changed it to 64-bit. What's disappointing is I don't see much difference between Windows Home Premium and Ultimate, besides the RAM and speed of the computer because of the higher RAM usage.
  6. Anonymous said:
    Hello,how much RAM can 64-bit use?

    Windows 7 Ultimate 192 GB
    Windows 7 Enterprise 192 GB
    Windows 7 Professional 192 GB
    Windows 7 Home Premium 16 GB
    Windows 7 Home Basic 8 GB
    Windows 7 Starter 2 GB

  7. Anonymous said:
    Hello,how much RAM can 64-bit use?

    It's 17 179 869 184 GiB

    2^64 = 18 446 744 073 709 551 616 B

    2^30 = 1 GiB

    18 446 744 073 709 551 616 - 2^30 * x = 0 => x = 17 179 869 184 GiB

    2^32 = 4 294 967 296

    4 294 967 296 - 2^30*x = 0 => x = 4 GiB
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