32-bit OS vs 64-bit OS

By Punkid
Jul 14, 2009
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  1. what are the advantages that i can get out of a 64bit Windows? i currently have 32bit Windows 7 RC

    and do 32bit software run on 64bit? if not then are 64bit software easy to find?
  2. rishicool2002

    rishicool2002 Newcomer, in training

    YES, 32bit program work on 64bit OS.

    To understand why 64-bit operating systems are a logical step in the evolution of the PC, consider this background information. Often the maximum size of the physical memory on a computer is less than the amount needed for all running programs. This is especially true when multiple processes or applications execute simultaneously. The solution for this is that programs store some of their data on the hard drive and copy it back and forth to physical memory as needed.

    This solution is often referred to as “virtual memory,” in which the computer simulates having large amounts of contiguous physical memory. A paging table is responsible for moving segments of virtual memory into physical memory as necessary. If the amount of memory demanded by all running processes exceeds the available physical memory (RAM), the paging table stores low-priority processes on the hard drive in the page file, which is much slower than RAM. When the user needs these processes, the page table remaps them into physical memory, where the user can access them at high speeds. The total number of addresses available in the virtual memory – the total amount of data the computer can keep in its working area for applications – is determined by the width of the registers on the computer processor.


    Until recently, almost all consumer PCs used 32-bit processors. The bit size of a processor refers to the size of the address space it can reference. A 32-bit processor can reference 2^32 bytes, or 4 GB of memory. These 32-bit processors were standard at a time when 4 GB was thought to be more than enough memory space for software applications on Windows. When a process, such as running a program, is created on an x86 Windows computer with a 32-bit processor, the operating system allocates its 4 GB of virtual memory, irrespective of the actual physical memory installed on a system. Half of that allocated memory is user-accessible memory, while the other half is for kernel processes such as drivers. Modern computing systems increasingly confront the 4 GB ceiling thanks to memory-intensive applications and the need to store multiple processes in memory simultaneously.

    In 2003, AMD released the first widely accepted 64-bit processor aimed at consumers, the Athlon 64, and coined AMD64 as the name for the new instruction set. Microsoft refers to the instruction set as x64, which parallels the widely accepted x86 nomenclature used for the instructions that run on most 32-bit processors. Per preferred Microsoft naming conventions, Windows Vista x64 Edition refers to the 64-bit version of Windows Vista in this article.

    Processors capable of referencing larger address spaces provide the opportunity to use more physical memory than ever before, potentially reducing the overhead spent moving processes in and out of physical memory. The 64-bit processors are theoretically capable of referencing 2^64 locations in memory, or 16 exabytes, which is more than 4 billion times the number of memory locations 32-bit processors can reference. However, all 64-bit versions of Microsoft operating systems currently impose a 16 TB limit on address space and allow no more than 128 GB of physical memory due to the impracticality of having 16 TB of RAM. Processes created on Windows Vista x64 Edition are allotted 8 TB in virtual memory for user processes and 8 TB for kernel processes to create a virtual memory of 16 TB.

    To summarize, the ability of Windows Vista x64 Edition to add address more memory space than previous versions of Windows helps minimize the time spent swapping processes in and out of memory by storing more of them in RAM.
  3. Punkid

    Punkid TechSpot Maniac Topic Starter Posts: 543

    thanks alot,programs such as games (crysis,mohaa,COD4,NFS pro street) will run perfectly right???? and is it advisable to install 64bit OS with 2gb of RAM or shud i first get another 2gb RAM?
  4. rishicool2002

    rishicool2002 Newcomer, in training

    32-bit vs 64-bit OS

    Buddy, you can play all kind of games that you have played till now on your 32-bit OS. Understand this that 32-bit OS doesn't recognise memory more than 3 GB. So whatever you'll install over 3GB, will not be used by the OS or any application running on that OS.

    Its recommended to first upgrade the RAM to more than 3 GB and then installed x64 OS on your machine. Please make sure that your hardware is 64 bit ready.
  5. Punkid

    Punkid TechSpot Maniac Topic Starter Posts: 543

    my processor is 64bit capable,wht other thing is there to check? and how much percent performance gain are we talking by going to 64bit?
  6. rishicool2002

    rishicool2002 Newcomer, in training

    There is nothing else you need to check.... The performance gain is not a lot. however, heavy games and applications, which requires lots of RAM to run, would run faster as they dont have to copy the data to pagefiles. Don't worry, its a good move to shift to x64 OS + more than 3 GB RAM. It also helps in running multiple application at the same time, without slowing down the system.
  7. Punkid

    Punkid TechSpot Maniac Topic Starter Posts: 543

    aight thats alot mate,ill go for 64bit when windows 7 is released on 22nd october :D
  8. superTramp92

    superTramp92 Newcomer, in training Posts: 26

    But aren't there still a lot of programs/applications out there that aren't compatible with 64 bit OS's?
  9. rishicool2002

    rishicool2002 Newcomer, in training

    Hey SuperTramp92,
    Microsoft has 70% of OS's market share. Most of the application vendors have worked at their end to ensure compatibility with x64 OS. There might be some application which are not compatible, however, it would be for those who aren't in the market too much.
    I've been using Vista Ultimate x64 since December 06, and never encountered a single sofware till date which has compatiblity issue... So choice is yours.. if you are willing to take a risk for compatibility over performance.!!

    Regards,
    Rishi
    Microsoft Server Support
  10. superTramp92

    superTramp92 Newcomer, in training Posts: 26

    Thanks rishicool2002, i'm going to wait until windows 7 comes out so that i can dual boot windows 7 64 bit with my windows xp 32 bit. That way, i have the best of both worlds.
  11. Punkid

    Punkid TechSpot Maniac Topic Starter Posts: 543

    hey ive installed windows 7 build 7600 64 bit,, but its no different than the 32bit,and i wanna know why all my programs are running in 32bit mode when i downloaded their 64bit versions?

    [​IMG]

    look at the Windows media player,even that is 32 bit,and i downloaded itunes 64bit but the apple servcies are 32 bit :| ... why is that??
     
  12. Rick

    Rick TechSpot Staff Posts: 6,304   +52 Staff Member

    ... Because for anything to run as 64-bit, it needs to be compiled as a 64-bit program.

    The 64-bit version of iTunes, for example, contains 64-bit compatible drivers for iProducts, but the majority of the program itself is 32-bit.

    The reason you don't see companies clamoring to rewrite all of their applications for native 64-bit operation is there's little benefit. Drivers, on the other hand, *have* to be 64-bit. Programs that use drivers for low-level access to hardware (virus scanners, backup utilities, firewalls, iTunes etc..) had to be updated to work with Windows x64 and sometimes have full 64-bit versions... But at the very least, the virtual device drivers they install are.

    For all intents and purposes, the only valid reasons to install Windows 7 x64 are you can have more than 4GB of RAM and it's going to be the gold standard in the next couple of years. If you don't care about those things, then there's no reason to install the 64-bit version of Windows.
  13. Punkid

    Punkid TechSpot Maniac Topic Starter Posts: 543

    well ive got the 64bit now and im not changing it cuz its no different than 32bit and i am having no compatibility,although i have 2gb ram atm , i am going for another 2gb soon so guess itll be useful
  14. Julio Franco

    Julio Franco TechSpot Editor Posts: 6,510   +308

  15. Punkid

    Punkid TechSpot Maniac Topic Starter Posts: 543

    thanks alot Julio,really helpful
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