Responding to questions from users about a lack of 64-bit support in the latest Photoshop CS3 beta, Byer in his official blog pointed out that many of the perceived benefits of 64-bit computing simply won't manifest themselves with current generations of hardware and software.
Byer said most Photoshop users are still running operating systems that only support 32-bit memory addressing for each program -- including Mac OS X Tiger, which can only assign 3GB per application. This, he says, eliminates the primary advantage of 64-bit technology: memory addressing beyond the 4GB barrier inherent to 32-bit software.
"Let's check all the 64-bit hype at the door," he wrote. "[64-bit apps] can address a much larger amount of memory. That's pretty much it. 64-bit applications don't magically get faster access to memory, or any of the other key things that would help most applications perform better."
In fact, Byer added that most of today's computers would actually incur a performance penalty as the code -- which is literally twice the size when accomplishing the same task -- would bog down the memory subsystem, reducing the amount of information that could pass through at any given time. Contemporary AMD and Intel processors only occasionally stand to gain from 64-bit code and often see their advantage negated by file caching.
The Adobe developer particularly rules out Mac development of a 64-bit edition of Photoshop CS3, blaming Tiger's fundamental 32-bit restrictions despite its selective 64-bit elements. "Many of the libraries an application would need to be fully 64-bit aren't available. So, on the Macintosh side," he wrote, "the answer [to the likelihood of a 64-bit version of Photoshop CS3] is zero."
While Byer says that he would love to update his company's star program and take advantage of more than 4GB of memory, he admits that the time spent on 64-bit technology would be better used for polishing the Universal Binary for Mac users and adding features that would be more immediately appreciated by artists looking to upgrade from earlier versions. However, he promises that a 64-bit edition is all but inevitable when more computers start using the greater memory space.
"It's a when, not an if," he wrote.