I've never really figured that out.

good question, Im wondering that too

32 bit is limlted to 4gb of memory use for each program (2GB is used by windows  so you only got 2gb left) . 64 bit uses twice the amount of space which means it's a little slower than 32 bit but 64 bit doesn't have the 4gb limit.

 A few games started to hit this 2gb limit  (this is virtual space)which causes the game to CTD after reaching the max. With 64 bit a developer has more memery  space for a program to run in.

32-Bit Vs. 64-Bit Windows

What’s the difference between 32-bit Windows and 64-bit Windows? – Spencer

This question is one that is deeply rooted in technology and one that could easily take more space than is available in this column, but here is my digest version.

In the computer world, bottlenecks are what cause those performance delays that we all detest and anything that can reduce the bottlenecks can improve performance.

In simple terms, the data path on a 32-bit operating system is half the size of 64-bit operating systems. That means that your computer can be slogging twice as much data around at any given time with a 64-bit OS.

Think 32-lane highway vs 64-lane highway: twice as much traffic can use the highway at any given time.

In the computer world, however, in order to take full advantage of the 64 lanes you need specially designated cars that are capable of using the extra lanes. Think of the extra lanes as only available for car pool vehicles that run on alternative fuels that are the color green.

In order for a 64-bit version of Windows to be of value to you, you will also need a 64-bit processor and 64-bit versions of the software that you plan to run. Without all three, you would be wasting your time.

Additionally, the 64-bit version of Windows can run faster because it can address more physical memory (generally referred to as RAM - Random Access Memory) and avoid using the much slower hard drive for active memory needs.

The 32-bit limitation for RAM access is @ 4 GB which means as soon as Windows needs more working memory it has to swap out information in temporary free space created on the hard drive (referred to as the swap file) and this is only if you have that much RAM installed.

Since most of us have much less than 4 GB of RAM, we are using the hard drive much more often for working memory, which is why we often find ourselves waiting for the computer to respond to our requests (meanwhile the hard drive light is flashing almost solid).

To really make things zing on a 64-bit system, you would want to install huge amounts of RAM (8GB or more) and again, only if your software programs can address this additional memory.

While all of this sounds like exactly what we have all been waiting for (both Linux and the MacOS have been 64-bit for many years), the reality in today’s computing environment is that you will be more likely to suffer from the compatibility issues that have always plagued the 64-bit Windows world than benefit from the advancements that it provides.

Unless you are building a computer that is specifically designed to run a special application such as 3D modeling, video gaming or work with massive amounts of data AND you have the discipline to only install applications that have been written as 64-bit programs or you do the research to ensure that whatever you install including your printer, scanner or digital camera software will not cause a problem on 64-bit Windows versions, your likely better off sticking to the 32-bit version that provides less headaches.

The best way that I can explain how to navigate this question is, if you have to rely on this column to make your decision about which way to go, stick to the 32-bit version.

Those technically savvy enough to make 64-bit Windows function well have little use for my advice column!

http://www.lockergnome.com/windows/2009/01/07/32-bit-vs-64-bit-windows/

Just get 64 bit. It's the future (well, its the now actually).

cool beans, thanks

One of the biggest practical differences is how much memory it can address and how much memory it can allocate to an application such as a game. In 32 bit, for most games it will be limited to, I think, just over 3gb using a 32bit like Win XP (still need mem for the O/S layer). But with 64b Win running it (in 32b mode of which most games are still native in) can allocate the full 4gb (ie 2 to the power of 32).

If the app is native 64bit, then many GB's can be allocated to the app however that also depends on which version of Win 64 you have as Win7 Pro 64b can address 192gb but Win7 Home Pre can address only 16gb.

Now the benefit of all this memory addressing comes into play on games a lot. I play Aion and when I switched from Win XP 32b to Win7 64b, Windows could allocate more memory to it without the need for having to shift the program in and off the HDD as much. The game now runs a lot less stuttered, but I did increase my physical RAM from 2gb to 6gb as well.

64 bit means it supports 64 bit processing and memory addressing. It gives little benefit unless you have applications that take advantage of 64 bit processing or if you want more than 4GB of RAM.

http://support.microsoft.com/kb/946765

64bit it's faster. but doesn't have 4gb limit.

can go as high as 256gb. but windows 7 it's limited to 8gb.

64bit it's only a bitch if you built your own pc, especially with custom things, making drivers to work are usually a problem but if u buy a sony, dell pc they ship you everything, drivers and apps.

then again 64bit windows can run 32bit apps with little problems, even games.

they run quite well if u have x86-64 cpu like intel core 2 duo, my p8600 2.4ghz 3mb of my notebook it's quite fast.

@Xoj

It all depends on the Win7 version in regards to the memory limitation. Most versions go to 192gb.

http://msdn.microsoft.com/en-us/library/aa366778%28VS.85%29.aspx#physical_memory_limits_windows_7

i know i said it could go as 256gb theorically, but min limit it's 8gb for home basic.