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Quick question :)

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  • User profile image
    Royal​Schrubber

    32 or 64 bit?

    I am moving from my old (really - it's ancient - P3) computer to my new core2 uber machine (I am like a child now, whiiiiii) - so what should I choose - 32 or 64 bit? Big Smile

    If I take 32 bit I can have more compatible system, but on the other hand - I could as developer more deeply prepare to 64 future...

    Quick answers please - what would you choose?

  • User profile image
    TommyCarlier

    Go for 64-bit. On a 64-bit CPU, you can run a 32-bit OS or a 64-bit OS. On a 32-bit CPU, you can only run a 32-bit OS.

  • User profile image
    TimP

    Go for 32-bit. There's more software and driver support and there's currently no compelling reason to run 64-bit on the desktop. I've seen no flattering benchmarks for 64-bit desktop software - it either runs as fast as 32-bit software or slower.

  • User profile image
    Secret​Software

    Go 64-bit, ensure you have virtualization on the hardware, and DEP on the hardware too.

  • User profile image
    TommyCarlier

    RoyalShrubber, are you talking about the CPU or the OS?

  • User profile image
    Royal​Schrubber

    TommyCarlier wrote:
    RoyalShrubber, are you talking about the CPU or the OS?


    OS. I have Core2 already (I got it 3h ago); I am choosing between 32 or 64 version of Vista, which I got through MSDNAA Smiley

    Well, if I’ll pick wrong one I can still format and reinstall Perplexed:)

  • User profile image
    ScanIAm

    For CPU, choose 64 bit.

    For OS, choose 32 bit.

    For video games, choose 8 bit Smiley

  • User profile image
    TimP

    thumbtacks wrote:
    
    TimP wrote: Go for 32-bit. There's more software and driver support and there's currently no compelling reason to run 64-bit on the desktop. I've seen no flattering benchmarks for 64-bit desktop software - it either runs as fast as 32-bit software or slower.
    Why is that? Was it just 32-bit software running in those benchmark tests? Are there sufficient resources (i.e. compilers) out there to take advantage of 64-bit from a developer standpoint?


    Some of it was desktop software like Adobe Photoshop and some of the other stuff was newer games which are 32-bit applications. The benchmarks showed no performance improvements running them on 64-bit operating systems. Even some games that have 64-bit versions usually have very little performance improvement. Unfortunately at the moment I can't remember which website had the benchmarks.

    On paper, you would think that 64-bit software and operating systems would have some performance benefit, if nothing else than because of the additional registers. I'm not sure if the technology is not mature yet or if the "64-bit future" is just a lot of hype. As it stands now, the only benefit of 64-bit computing will be when computers start coming with more than 4GB of RAM since, from what I've read, the extended addressing in 64-bit processors is quite a bit more efficient than using PAE to get at the memory.

  • User profile image
    atehrani

    64-bit, provided you have mature driver support for your devices.

  • User profile image
    AndyC

    thumbtacks wrote:
    I would think if you wrote a true 64-bit app, that maybe could not be run on a 32-bit machine, at that point you *should* see a performance difference.


    64-bit is not about being faster. 64-bit is about being able to access larger amounts of memory.

  • User profile image
    Secret​Software

    AndyC wrote:
    
    thumbtacks wrote: I would think if you wrote a true 64-bit app, that maybe could not be run on a 32-bit machine, at that point you *should* see a performance difference.


    64-bit is not about being faster. 64-bit is about being able to access larger amounts of memory.


    Does that not mean better performance ?

  • User profile image
    Cannot​Resolve​Symbol

    AndyC wrote:
    
    thumbtacks wrote: I would think if you wrote a true 64-bit app, that maybe could not be run on a 32-bit machine, at that point you *should* see a performance difference.


    64-bit is not about being faster. 64-bit is about being able to access larger amounts of memory.


    Actually, if an application's written for a 64-bit processor, you can process more data at a time than a 32-bit processor would.  For example, an operation on an Int64 (say, complement, for simplicity) would take two cycles (at least) on a 32 bit processor while it would only take one on a 64-bit processor.

  • User profile image
    BlackTiger

    Hmmm... All dual-core CPU are 64-bit already.

    But better to choose 32-bit OS. There is no single reason to install 64bit OS (except MAC OS Smiley ). 64bit OS isn't faster, sometimes they are even slower. Do you really need more than 4G of RAM for desktop applications? Smiley "More secure", "more advanced", "much better"? Just ordinary marketing lie.

    If you stumbled and fell down, it doesn't mean yet, that you're going in the wrong direction.
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  • User profile image
    TimP

    AndyC wrote:
    
    thumbtacks wrote: I would think if you wrote a true 64-bit app, that maybe could not be run on a 32-bit machine, at that point you *should* see a performance difference.


    64-bit is not about being faster. 64-bit is about being able to access larger amounts of memory.


    That's the impression I get. So can someone explain why anyone would want to run a 64-bit operating system at this point in time?

  • User profile image
    AndyC

    thumbtacks wrote:
    Although I have not perused the latest Intel specs, doesn't 64-bit mean larger registers also?


    Yes, but how useful is that?

    On 8-bit processors the biggest number we could deal with in one go was 256, so lots of performance was lost breaking things up into separate steps.

    16-bit came along and we could deal with up to 65536 at once. Better, but still not great. Lots of things we have to deal with still don't quite fit. Less steps means better performance, but by no means optimal.

    32-bit was the sweet spot, now we could deal with up to 4294967296, which happens to be quite enough for almost everything we need to deal with on a daily basis. Fantastic.

    64-bit lets us deal with much, much bigger numbers in one go, but it turns out we mostly don't need to. If we did, we'd just be shuffling zeroes around all the time, which helps nobody.

    As it turns out, there are some speed benefits from other features added to the processor (more registers etc) but none of these are inherently 64 bit features, it was just a good time to add them.

  • User profile image
    Royal​Schrubber

    BlackTiger wrote:
    Hmmm... All dual-core CPU are 64-bit already.


    Not precise enough - although most of them are, mobile Core Duo is 32 bit only, and you can find yourself in tricky situation when buying laptop if you do not know that... Core2 is the way to go Big Smile

  • User profile image
    ScanIAm

    AndyC wrote:
    
    thumbtacks wrote: Although I have not perused the latest Intel specs, doesn't 64-bit mean larger registers also?


    Yes, but how useful is that?

    On 8-bit processors the biggest number we could deal with in one go was 256, so lots of performance was lost breaking things up into separate steps.

    16-bit came along and we could deal with up to 65536 at once. Better, but still not great. Lots of things we have to deal with still don't quite fit. Less steps means better performance, but by no means optimal.

    32-bit was the sweet spot, now we could deal with up to 4294967296, which happens to be quite enough for almost everything we need to deal with on a daily basis. Fantastic.

    64-bit lets us deal with much, much bigger numbers in one go, but it turns out we mostly don't need to. If we did, we'd just be shuffling zeroes around all the time, which helps nobody.

    As it turns out, there are some speed benefits from other features added to the processor (more registers etc) but none of these are inherently 64 bit features, it was just a good time to add them.


    I'm pretty sure that any data that is moved/copied in memory is done so through the registers, so moving data at 64bits at a time can improve this process.

    Multimedia and driver type stuff should be sped up if they can manipulate data 8 bytes at a time, no?

  • User profile image
    RichardRudek

    I'm not too sure about how much of benefit 64-bit general purpose registers would bring, given that that SSE gives us 128-bit registers. But there may be some gains for various file and filesystem stuff - ie lower latency (less clock cycles) using the General Purpose Registers as opposed to SSE Registers. But how much of a benefit is the issue.

    Then there's the virtual address space benefits. I remember seeing/hear one of the microsoft.com website people explain (on Ch9) how using the 64-bit servers (2003 ?) really helped them improve reliability of their site(s), primarily because WOW64, that is Windows (32) On Windows 64, gives them a much "cleaner" 2GB virtual address space (less holes), and more to the point, they can get close to the full 4GB of virtual address space, if necessary - apparently, the Kernel is not fully mapped into each process' address space. At least, that's  what I recall - I suppose I could actually look it up... Wink


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