Difference between x86 and x64

Hello again, I know this might seem like a newbie question, but I think this would be useful to anyone wanting to know.
I know that x86 = 32bit version, and the x64 = 64bit version.
and i know that the x86 requires less memory than x64.
But what i want to know is, what is the main differences, is it faster, is it worth while, and why does it require more memory?
One more thing would it be worthwhile for me to upgrade from 1gb of DDR2 RAM to 3gb? would i see a significant difference?
Thanks in advance

There's an article here which covers some of those points:

Windows 7: 64 bit vs 32 bit?

It's not as black and white as being faster or better - as it depends on the hardware you are going to be using it on. If you have more than 3GB of memory than I'd strongly suggest going for the 64 bit version as you will need that to be able to address it all.

However, you'll get a performance boost when going from 1GB > 3GB in either version of the OS. Memory is cheap at the moment so it may be a good time to do it.

Thanks Ian for that, so it is definitely worth while to buy 2gb more, to make it 3gb.
What I was thinking was, I might upgrade to the 3gb, wait until W7 becomes available publically, or the offer MS have released; and then install 64bit version on that, is that a good idea or not?

For what it's worth, I have installed various leaked builds of the 64-bit version of Win7 on my machine which has only 2gb. It ran like a dream. I think it was "snappier" than 32-bit, but not in a measurable sense. The only issue I ever had was running an older game, which I really like playing a lot, so I have reverted back to 32-bit.

MS states that 2gb is the minimum for 64-bit, and 4gb is the level at which you're really starting to see benefits.

You have a variety of options, try them all!!

I would suggest having 4GB minimum of computer memory if you plan to use 64bit. The OS and some 64bit programs will use a little more memory as compared to their 32bit counterparts, and you might end up with slightly worse performance if you have less than 4GB of RAM. A 32bit OS can make use of 3GB just fine.

I beg to differ. I am using 2 GB of ram just fine on the 64 bit version. The operating system uses only about one of those gigs, and I can use the other for games and other heave processing loads without a problem. I'd say thats all you really need unless you want to use incredibly memory-intensive stuff like 3D event simulators or something like that.

Would ready boost my 2gb removable usb drive be worthwhile?

I have 4GB USB drive dedicated to ReadyBoost, and to be honest, I don't know if it makes any difference or not. I know windows is using it, because the access light flashes from time to time. With the low costs of USB thumb drives these days, it doesn't hurt to dedicate one to RB.
Found this article (it is a bit old): http://www.activewin.com/reviews/har...adyboost.shtml
This one is about 2 years old: http://www.pcstats.com/articleview.c...id=2160&page=1