Is 64-bit Vista really faster than 32-bit in practice?

well, the first and last links are talking about the same small test done by Adrian Kingsly Hughes at Zdnet (hardware 2.0) - his results showing Vista is faster than XP are probably not the last word on the subject but they are still impressive and if nothing else they should help to dispel the oft repeated canard that Vista is somehow noticeably slower than XP.

As for 32 bit Vista being slower than 64 bit Vista or vice versa (there is some overhead in the longer word length of 64 which some will claim takes a performance hit) I think it is very hard to say and I'd wager there is actually not that much difference, all things equal, but things may not be equal for other reasons..

One thing to consider is that you have a different set of drivers for 64 than you do for 32 so this could account for some difference in performance too.

If you look at all the bench marks and published articles on the subject you will find many differing opinions and results so it may be that nobody actually knows what, if any, difference there is at this time.

As Arges pointed out above if you actually have applications coded to use 64 and thus will allow the system to operate on larger chunks of data at a given time then yes, there is a performance gain at least in some applications. The new Photoshop is one such application and I do believe it is significantly faster under 64.

The problem right now is that precious few apps are coded for 64 and thus they run under a 64 bit system in 32 bit mode.

The only major advantage at this time (assuming you are not a photoshop junkie or else a user of some other specialized 64 bit app) is that 64 will allow you to use a lot of RAM. Depending on your application and on how much stuff you are running simultaneously this can speed things up considerably and may even affect stability as there could be less crowding in your memory space.

All in all users of Vista 64 have been reporting they are very satisfied with it. I use it with 8 gig of RAM and I love it - best experience ever on an OS of any kind , and I've tried a lot over the years. I am amazed that I can have two virtual machines open, running XP and Linux, a web browser or two with a ton of tabs open, any number of other apps and bkg apps running and still I could fire up Crysis and play it with little or no performance hit and nary a crash.

Another thing to consider is that Vista also uses a very intelligent and aggressive pre-caching system called 'superfetch' and when you throw 8 gig at superfetch it will fill up as much as half of it, 4 gig worth (maybe even more on some occasions) with frequently used code and in my experience this makes Vista 64 very snappy indeed - most of my usual stuff pops up instantly.

Well, now that you mention it I'm sure the extra core (I've only got a dual) is a big part of that but I'm pretty sure the RAM is too. As for the OS, aside from the fact that it is 64 bit and using all that RAM, it is hard to say if Vista is any better written for multi-core or memory management than XP, it might actually be, as some have claimed, certainly superfetch must figure in too, bit I cannot say for sure one way or the other.

There is no "Emulation" between 32 and 64 bit Windows. It would be, and is, completely unnecessary. In one sentence: x64 includes all the instructions in the x86 spec and it is *all* written to Windows API's.



(In advance - I am grossly over simplifying things for the sake of explaining the concepts. And ask that those more technical than I withhold the flames and instead add their kind wisdom)


Not technically accurate, but I find it easiest to think of it like a sandwich - The CPU on one side, and the operating system on the other.


On the processor side:

The CPU reads the actual binary code, which is presented in the form of instructions. These instructions are the "x86" and "x64" that you read/hear about. Understand that the X64 instruction set includes everything in the x86 - So any x64 processor can and will fully handle anything that's x86.

Therefore, as long as the game was compiled to the x86 (32bit) standard, the CPU can fully understand and run it because they are 'speaking' the same language.


On the side of the OS: There is a similar mechanic, though here it's called an "API" (Application Programming Interface). In very broad terms, it works like the instructions sent to a CPU: These are the commands and formats programmers use to talk to the Operating System, which they use to access system resources like memory and information on the hard drive. You can think of it like the teller window at the bank: It's your way to pass an instruction inside in order to get the result you want. When you go to the teller (API), you have to give her a message (instruction) that she understands, right? The OS wants to see some Function (Withdrawl), the location required (Account #), and some data set (how much). If you give the teller (OS) that, then you'll get your twenty bucks.

As long as the program (game, whatever) follows the proper API's then it will run on the Operating System.

So: Just so long as a given (32 bit) game is written to the proper Windows (Vista) API's, and compiled to run on an x86 processor, then it *will* run on 64 bit (Vista).


Generally speaking, when you hear about incompatibilities it's because the programmers who wrote a given application either did not adhere to the proper API spec when they wrote their code, or because they took short cuts (which may no longer work), or because the (new) Operating System's API set is different from the old one.



IN PRACTICE - There is little difference to the user between 32 and 64 bit Windows. Certain aspects may be a few percent weighted one way or the other, but from an end user perspective they look/feel/play pretty much the same. WOW64 doesn't 'emulate' - it plays a few games with pointers and registry entries in order to smooth the coexistence. That is all.


{Edit} If you want/need deeper technical knowledge of the inner workings, then I highly suggest that Tom's Hardware, like most internet message boards, is not the proper place to find accurate information. Rather, you should use TechNet and MSDN to confirm Windows related detailia, and buy/obtain the actual instructional and educational manuals for both general and windows specific theory. - You don't need to pay a subscription fee to use the boards there.

{EDIT part Deux} http://msdn.microsoft.com/en-us/li [...] S.85).aspx

It's all to do with how the applications (including the O/S) use the 64 bit capabilities of the CPU.

Fundementally, the newer operating systems are being written to take advantage of the 64 bit registers of the CPU (thus, the reason for a 32 bit version and 64 bit version of the O/S). Yes, the memory address space is larger with a 64 register to address memory.

For most applications however, there won't be a difference in perceived performance just by switching to a 64 bit O/S. That's because for most applications, 64 bit wide data is not needed (in quite a number of instances, data that is 16 bits or 32 bits wide is enough --- example when counting/looping).

For the applications that are 'number crunchers'... there will be a difference. Those will be mostly mathematical, statistical or analysis type of applications (usually used by businesses, academics, digital media producers).

Also, the GPU (Graphal Processing Unit - or graphics chip) will make a difference in the newer O/S'es. If your PC has a high-end GPU, the O/S will use that for processing graphical rendering rather than the CPU. Thus if you have 64 bit O/S with a good GPU there will be hardly a difference between that and the same PC with the 32 bit O/S.

Hope this answer helps!

- Nalin Jayasuriya

what kind of diffrence is seen between the two when utilizing lower amounts of ram say 2g instead 8 or even 4g.

This topic has been closed by Area51reopened