Overlag, I have never said it was a bad thing (you really are way to sensitive about this), and Cav, you misunderstood what I was saying, but ended up agreeing with me anyway.
The AMD64 can be an AMD32 and the improvements would be the same, as far as performance gains goes. Like you said Cav, it is more due to being a better design. There is nothing inherent in moving to 64bit which would improve performance.
Before you can understand why the move to 64bit is not a big deal, you have to understand why it was a big deal in the early days.
The moves from 8 to 16 to 32 bit were all good things which allowed programmers to use larger numbers without jumping through hoops. These migrations naturally brought better performance as now a programmer could directly reference a number that use to require several register loads and reads and stores in an array.
However, in the jump from 32bit to 64bit, it is the rare application which needs a number larger than 32bits. Games certainly do not need them. This is why the performance difference is not going to be that great. Indeed, Microsoft's own compiler wiz has already stated most applications will run worse in native 64bit mode versus the 32bit counterpart. It is pretty easy to understand why, when you know exactly how it all works.
Oh, and SSE2 is still slow on the AMD CPU as compared to even the Prescott. Just saying.
EDIT: Tha FarCry stuff is not an apples to apples comparison. I have no doubt it runs better, but it is not due to being compiled as 64bit. Of that, I can assure you.
EDIT2: I just read what they did in FarCry. CryTech should be shot. This is a marketing patch if I ever saw one. AMD must have shoved some money thier way as the *patch* does things only in the 64bit version, which can be done in the 32bit version but CryTek is not going to do it.
In other words, the optimizations done for the 64bit *patch* can be done for the 32bit version, they simply are choosing not to.