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  • #2268445

    Maximum amount of memory


    by scolas ·

    Hi gurus,

    I have to create a datamining server on a windows server and I was wondering which quantity of RAM I can put with a windows platform.

    I understood that windows supports 4 Go RAM, I’m right ? :/

    for various reasons, I’d like 16 Go of RAM.

    Do I have to use XP or w2003 server ?
    Do I have to use Itanium CPU ?



All Answers

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    • #2509996


      by scolas ·

      In reply to Maximum amount of memory


    • #2509970

      Don’t bother with Intel CPU, go with AMD Opteron 64x for 16GB

      by why me worry? ·

      In reply to Maximum amount of memory

      The 32 bit CPUs’ max out at 4GB at the O/S level, even if the BIOS recognizes more RAM. Go with a 64 bit AMD Opteron and you won’t be sorry….trust me. I’ve set up numerous HP Proliant DL385 Opteron’s with 16GB RAM and Windows Server 2003 Enterprise 64x edition and have yet to see them go down or exhibit any problems.

      • #2536830

        to be sure

        by scolas ·

        In reply to Don’t bother with Intel CPU, go with AMD Opteron 64x for 16GB


        if i understand, the problem is 32 bits architecture not windows. I have to buy 64 bits architecture (with let’s say AMD, but I probably can’t choose) to manage correctly the 16 GB of RAM.
        As I have 64 bits architecture, I must use windows 2003 or XP 64x edition.

        Right ?

        • #2654915

          No, That is not true at all. Here’re the facts you need

          by khongphutu ·

          In reply to to be sure

          Here’re the facts for Windows OSes:

          What was said was completely false!

          But this is only for various Windows versions, or what I refer to as Operating System (OS) perspective.

          You must also decide on the hardware perspective. The chipset on each motherboard dictates the maximum capability, but what is actually implemented by each hardware vendor (Dell, HPQ, IBM, etc) is often a subset of all the features and capabilites supported by that chipset). The hardware vendor decides on the intended use of each host and the intended market, and decide on how much memory to be supported by that host. This decision ties directly on the type, and number of CPUs. From this, you get the maximum supported physical memory. This is independent of which OS you choose to run on it.

          Next is the maximum OS supported memory. This is dependent on which OS and which type of OS. Again, for Windows, refer to

          Windows 2003 comes in 3 architectures, namely 32-bit X86, 64-bit X86 (X64), and Itanium 64 (IA64). Within each architecture, there are several versions, which supports various classes of intended user, from home users, to Data Center.

          Itanium is the orginal 64-bit hardware architecture which is expensive, and not much software are available so it’s not popular.

          32-bit X86 architecture is cheap and very popular, but demand for more memory support both at the hardware and OS levels, make this fast becoming phased out by large corporations that demand high performance servers.

          Then come the compromising/ bridgegap effort on Intel’s part to compete with AMD on the marketing war. Intel comes out with the Intel X86 X64 architecture (where the X86 designates the xx386 and the X64 designates the 64-bit archtecture). Microsoft worked with Intel to release Windows 2003 X64 and Windows XP X64, or more often abbreviated as W2K3 X64 /XP 64 to differentiate from W2K3 IA64. Windows X64 is NOT a 64-bit emulation. It’s an OS that have both the 32-bit and 64 bit kernels.

          To run W2K3 X64 or XP 64, you must have the hardware that supports the X86 X64 architecture and you must also have an OS that supports the same architecture, down to each single driver for each hardware component in that host that you intended to use.

          The major advantages of W2K3/XP X64 is that you can run both 32-bit applications and 64-bit applications on the same hardware host and OS. Furthermore, W2K3/XP X64 also increased the maximum OS-supported memory. But again, you can’t get to these limits unless your hardware support it first.

          If you only have 32-bit hardware which support let say 64 GB of memory and you want to use all of these memory, you must use a 32-bit OS that can support that much memory. For Windows 2003, this would be either Windows 2003 Enterprise Edition, or Windows 2003 Data Center Edition.

          Hardware that support X64 architecture also support 32-bit OSes in addition to 64-bit X64 OSes. AS example, the Dell PowerEdge 2950 servers can be used to run:
          a. 32-bit Windows
          b. 64-bit X86 Windows
          c. 32-bit Linux*
          d. 64-bit Linux
          e. 64-bit Solaris X86

          So it’s not true that if you have 64-bit architecture you must use Windows 2003 or X64x edition (RH Linux will install as 64-bit by default).

          It’s also not sufficiently precise to simply refer to 64-bit architecture. The IA 64 is a 64-bit hardware architecture and there is Windows 2003 IA64 that runs on it. The point here is when it comes to 64-bit architectute, you can’t just say 64-bit architecture since it’s not clear as to which one you’re referring to. instead, you MUST specify either IA64 or X64 architecture.

          The 4GB limit is per-process limit for 32-bit addresing scheme. Not to be confused by so many people with 32-bit architecture limit (max theoretical limit) supported by Windows, as evidenced by the fact that 32-bit Windows servers can supports up to 128GB of RAM in the Windows 2003 Data Center Edition.

          I’ve set up many Compaq servers [all rack mounted] (DL385, DL585) and many Dell PowerEdge servers (PE 1950, 2850, 2950, 2970, 6450, 6950) and Sun V20Z, V40z. I have performed performance assessment so I’d think I know what I am talking about. Check it out for yourself and you’ll know where the truth lies.

          As for your questions, these are loaded questions because they do not have any info on how big your databases are, how many querries, how much time per day you have to querry these DBs, how fast you have to complete these querries for each of the DB. All I can say is that if you want to use XP, you’ll have to use XP X64 which supports up to 128 GB, or W2K3 Enterprise Edition X64 which supports up to 1 TB. These would requires X64 hardware and X64 drivers, and your software can be either 32-bit or 64-bit. On the other hand, if you only have 32-bit hardware, then you’ll have to use Windows 2003 Enterprise Edition at the mimimum in order to have 16 GB memory support (see

          Your decision is ultimately based on your budget constraints (for hardware and OS) vs. performance constraints (how fast must the datamining be completed for the size of [each] of the DBs to be datamined)

          I think I’ve delineated all the revelant info. Let me know if I missed anything.

          Good luck.


    • #2655011

      This explains it

      by jhrave ·

      In reply to Maximum amount of memory

      it is all shown here and yes it is the architecture, of the OS not of the CPU, 32 bit only reads 3 GB properly, and 2003 server only a certain edition reads more the 4 gigs, I suggest a 64 bit os I am dual booting xp x64 and vista ultimate x64 for mine.

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