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

Although its true that 32-bit will be around for a while in some form or another, Windows Server 2008 R2 ships with a 64-bit SKU only. I would not be surprised to see WOW64 as an install option as early as Windows 8 as more software migrates to 64-bit. WOW64 is a install, memory and performance overhead. The 3.5GB RAM limit in 32-bit Windows along with increasing RAM densities will encourage this migration. I'd rather have more RAM than CPU...

Embrace 64-bit! Take the time to make your 32-bit code 64-bit compatible, its a no brainer and straightforward. For normal applications the changes are more accurately describes as code corrections. For drivers the choice is: adapt or lose users. When the time comes you'll be ready to deploy on any platform with a recompile.

IMO the current cache related issues are moot; silicon improvements in this area and further 64-bit optimisation will be forthcoming.