Originally Posted by OTSS
What is the main difference? I know x64 support more ram (or so I have heard) But I am going to be using 4GB. Is there any other differences performance wise? I am going to get the OEM version but don't know which one to get. I am mainly getting it for directx 10 otherwise I would still be using XP.
Your thinking of 64 bit vs 32 bit processors. x86 refers to a generic and most popular commercial processor architecture; something else entirely really.
As you said in 64-bit windows recognizes 4gb's of ram. However just b/c vista does not officially recognize all the ram, doesn't necessarily mean your computer can't use it. Its more complicated then that.
64-bit is the future of computers. A bit to your processor is a 0 or 1. All the calculations for everything your computer does is translated into a series of 0's and 1's. So if your processor is a 64-bit, that means it can handle a series of 64 0's or 1's in one calculation.
However if you have a 32-bit processor, then to do the same calculation with the 64-bit number it most perform 2 steps instead of 1. Thus slowing it down.
So a 64-bit OS supports the use of 64-bit processing. It's faster, while not by a factor of 2 as one would logically assume since other things come into play too, but it is signifigantly faster. A 64-bit OS can also more effectively address memory, meaning it can make better use of the RAM you do indeed have installed; however this is really more noticeable in servers.
So why would anyone go with 32-bit?
Well 64-bit Operating systems tend to cost more. Not sure on the price difference however, you could look that up. But in order for a program to take advantage of 64-bit processing, it has to be specifically written to do so. And not many programs today are done as such, (probably the majority of the programs you use aren't coded for 64-bit processing). 64-bit OS' are often less stable resulting in more problems. Also the programs written for 64-bit tend to be less stable also. So you have less stability in your OS and your programs.
64-bit benefits are not really seen in things like surfing the web and office applications, as 32-bit is perfectly adequate for this application. However for things that are graphic intensive and require intense scientific calculations, (Photoshop, Games, 3D Rendering, video and music editing, etc.). So if you don't do those things opt for the more stable 32-bit OS. If you do those things rather frequently, opt for the 64-bit if its in your budget.