KomaWeiß, on 04 November 2012 - 02:27, said:
The problem is many developers still won't make 64bit until Microsoft ditches 32bit Windows. >.<
So long as an application has no need to access more than 2 GB of memory (assuming
defaults), having a 64-bit binary isn't an absolute necessity. Though one valid reason to require 64-bit binaries is if it's an Explorer extension and of course drivers. Your browser or PDF reader doesn't need to be 64-bit especially if it's portable.
The OS being 32-bit or 64-bit is a different case. People don't realize the loss of user-accessible memory if they complement a standard system with 4 GB of RAM (which perhaps they heard from others is the upper limit) with a discrete graphics card whose VRAM cuts into that limit.
I suppose, though feel free to correct me wrong, any speed differences if noticed is down to the reduced need of throwing away data in memory to meet limits in a 32-bit environment, plus a boost to computational-related tasks due to the number of CPU registers - those aren't a night and day difference though in most everyday applications.