On a side note, there are a few applications which truely benefit from
a 64-bit architecture and would be much slower in 32-bit ones.

  One excellent example are computer chess programs. The best chess
computers in the world have always been 64-bit, and for a good reason:

  Bitmasks of the chess board are an efficient technique to speed up
calculations. For instance, one bitmask could tell to which squares
a certain piece can move. Performing a logical and of this bitmask and
another telling the location of another piece tells the program really
fast (in 1 clock cycle or less, depending on the processor) whether the
latter can be captured by the former. This technique is used a lot in
the best chess software out there.

  Now, a bitmask of the chess board requires, naturally, 64 bits (because
that's the amount of squares in the board). In a 64-bit processor it's
the size of a register, and thus performing operations on these bitmasks
is really fast. In 32-bit processors 2 registers (and thusly two operations)
would have to be used for each bitmask and each operation done to them,
making it considerably slower.

  Unfortunately these special cases are rather rare, and for example
POV-Ray is not a program which would benefit much from 64-bit integers
(except for the added address space if there's more than 4 gigabytes
of memory in the computer).

-- 
                                                          - Warp

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