ok, I did some research about memory usage, 32 and 64 bit. This is what I got:
32 bit Windows:
max 2 GB memory per task
max 4 GB memory per OS (some of them gets lost because of addressing the hardware)
64 bit Windows:
max 4 GB memory per task
max 128 GB memory per OS (theoretically it would be much much more)
This shows me that I need much more memory to use a 64 bit OS efficiently.
[..]
So it will only make a difference if I have more than 4 GB RAM in my PC.
Nope, it will still matter if you're multitasking. The assumption that you also need more memory to use a 64 bit OS is untrue. Programs demand memory, 64-bit handles it differently, but it won't need for example twice the amount of memory (addressing).
Also, note that not every 64bit edition of Vista actually really supports more than 4Gb.
I also read that the 64-bit version of the game "Crysis" was not faster than 32-bit. They told that it actually was faster but the longer addressing slowed it down at the same time. So it was the same like 32-bit at the end.
And Crysis does not use more than 2 GB RAM (32 and 64-bit).
With 64-bit gaming, depending on the efforts of the developer, it will often improve the overall visual quality because of the higher detail, but naturally at a loss of performance. It'll obviously ask a bit more of your processors, but it's not a world a difference.
It's like running a game at insanely high settings with a top of the line graphics card, it might run 40fps... bút look superb. Same game, lower graphics settings with a budget 3D card might run at over 60fps, but look horrible.
Cheers
