Porting 32 bit C++ code to 64 bit - is it worth it? Why?

Question

I am aware of some the obvious gains of the x64 architecture (higher addressable RAM addresses, etc)... but:

• What if my program has no real need to run in nati

Answer 1

Unless there's a business reason to go to 64 bit, then there's no real "need" to support 64 bit.

However, there are some good reasons for going to 64 bit at some point, aside from all those that others have already mentioned.

• It's getting harder to buy PCs that aren't 64 bit. Even though 32 bit apps will run in compatibility mode for years to come, any new PCs being sold today or in the future are likely to be 64 bit. If I have a shiny 64 bit operating system I don't really want to run "smelly old 32 bit apps" in compatibility mode!

• Some things just don't run properly in comptibility mode - it's not the same thing as running on a 32-bit OS on 32-bit hardware. I've run into a few issues (e.g. registry access across the 32/64 bit registry hives, programs that fail because they're not in the folder they expect to be in, etc) when running in compatibility mode. I always feel nervous about running my code in compatibility mode - it's simply "not the real thing", and it often shows.

• If you have written your code cleanly, then chances are you only have to recompile it as a 64 bit exe and it'll work fine, so there's no real reason not to give it a try.

• the earlier you build a native 64 bit version, the easier it will be to keep it working on 64 bit as you add new features. That's a much better plan than continuing to develop in the dark ages for another 'n' years and then trying to jump out into the light.

• When you go for your next job interview, you will be able to say that you have 64-bit expeirence and 32->64 porting experience.