XP/Vista 32 bit vs 64 bit

Discussion in 'General Chat' started by hac981, Feb 1, 2007.

  1. hac981

    hac981 New Member

    I am curious why so many people want to jump on the band wagon and get Vista and also curious as to why people want to use 64 bit systems. What real advantage is there? Is there any understanding of 32 bit vs 64 bit and what companies who supply software have to do to supply software for 64 bit systems?
    I cannot say I understand all there is to know about O/S's and 32 bit or 64 bit storage systems but I do know it is a hassle to create software that will work on systems with different requirements such as 32 or 64 bits. It requires a compiler that has the capability to compile the code for various bit sizes then you have to take the sorce code for a program such as Anydvd and compile it for the OS/bit size in question.
  2. DetroitBaseball

    DetroitBaseball Well-Known Member

    64-bit is better.
  3. oldjoe

    oldjoe Well-Known Member

    64 bit, in theory, doubles the amount of data a CPU can process per clock cycle.
    Whether you notice that speed in everyday computing is questionable. You will see it in benchmarks.
    I have one PC running a 64-bit CPU (P4 3,0) running XPPro 64Bit and I do not see any noticeable increase.
  4. RedFox 1

    RedFox 1 Super Moderator

    Not necessarily. It all depends on what applications you are running.
  5. DetroitBaseball

    DetroitBaseball Well-Known Member

    A common misconception is that 64-bit architectures are no better than 32-bit architectures unless the computer has more than 4 GiB of memory. This is not entirely true:

    * Some operating systems reserve portions of process address space for OS use, effectively reducing the total address space available for mapping memory for user programs. For instance, Windows XP DLLs and userland OS components are mapped into each process's address space, leaving only 2 to 3.8 GiB (depending on the settings) address space available, even if the computer has 4 GiB of RAM. This restriction is not present in 64-bit Windows.
    * Memory mapping of files is becoming less useful with 32-bit architectures, especially with the introduction of relatively cheap recordable DVD technology. A 4 GiB file is no longer uncommon, and such large files cannot be memory mapped easily to 32-bit architectures; only a region of the file can be mapped into the address space, and to access such a file by memory mapping, those regions will have to be mapped into and out of the address space as needed. This is an issue, as memory mapping remains one of the most efficient disk-to-memory methods, when properly implemented by the OS.

    The main disadvantage of 64-bit architectures is that relative to 32-bit architectures the same data occupies slightly more space in memory (due to swollen pointers and possibly other types and alignment padding). This increases the memory requirements of a given process and can have implications for efficient processor cache utilization. Maintaining a partial 32-bit model is one way to handle this and is in general reasonably effective. In fact, the highly performance-oriented z/OS operating system takes this approach currently, requiring program code to reside in any number of 32-bit address spaces while data objects can (optionally) reside in 64-bit regions.

    Currently, most commercial software is built as 32-bit code, not 64-bit code, so it can't take advantage of the larger 64-bit address space or wider 64-bit registers and data paths on 64-bit processors, or, on x86 processors, the additional registers in 64-bit mode. However, users of free or open source operating systems have been able to use exclusive 64-bit computing environments for years. Not all such applications require a large address space or manipulate 64-bit data items, so they wouldn't benefit from the larger address space or wider registers and data paths; the main benefit to 64-bit versions of applications that wouldn't benefit from them would be that x86 versions would be able to use more registers.