Originally Posted by amm37
whats the difference between the 32 and 64 bit versions?
Well I don't want to get into the whole engineering of computer architecture here, but let's just say that one can process and transfer data in chunks twice as big as the other. This doesn't make a 64-bit system necessarily twice as fast as a 32-bit system, however, because a lot of the data that gets pushed around in a processor comes in chunks inherently smaller than 32-bits. But some calculations or memory accesses can be performed in half the time on a 64-bit system because the pipe that the data is flowing through is basically twice as wide.
Also, 32-bit architecture is only capable of addressing up to 4GB of memory (because the largest number that can be stored in a 32-bit register is 4,294,967,295 = 4GB). 64-bit architecture allows for a virtually limitless amount of memory (2^64 = 18,446,744,073,709,551,616).
Finally, for mathematical calculations involving numbers greater than 4 billion (2^32, to be precise), 32-bit architecture is extremely slow because the numbers cannot be stored in a single register. If you're adding or multiplying a bunch of really, really, really, really big numbers then a 64-bit system will make a huge improvement for you.