Almost everywhere I download software, I see a 32-bit version and a 64-bit version of the software. My questions are
32-bit vs. 64-bit
As the number of bits increases there are two important benefits.
32-bit systems were once desired because they could address (point to) 4 Gigabytes (GB) of memory in one go. Some modern applications require more than 4 GB of memory to complete their tasks so 64-bit systems are now becoming more attractive because they can potentially address up to 4 billion times that many locations.
A 64-bit application will require more memory to open any particular file than a 32-bit application, because the address sizes of memory pointers and other structures automatically become larger. This means a user should have a minimum of 4 GB of memory installed to benefit from a 64-bit application.
Performance of 32-bit vs. 64-bit apps:
Unless you need to access more memory that 32b addressing will allow you, the benefits will be small, if any.
When running on 64b CPU, you get the same memory interface no matter if you are running 32b or 64b code (you are using the same cache and same BUS).
Check out [1], [2], [3] for more info.
When to provide 32-bit vs 64-bit softwares:
The choice is tough to make. You have to consider a lot of staffs before determining a 32-bit or 64-bit software, for example:
Moreover, the following articles that you maybe interested in during this choosing:
