Adobe has announced that its next version of Photoshop will include 64-bit capacity, but due to a recent Mac programming quirk, the higher-rate application will only be available for Windows.
While the company generally keeps features in the Windows and Mac versions of its products at a level of parity, it was not possible with the latest version of Photoshop because of a change Apple made last year to Mac's programming underpinnings, according to John Nack, Adobe's product manager for Photoshop.
"We're not going to ship 64-bit native for Mac with CS4," Nack said. "We respect Apple's need to balance their resources and make decisions right for that platform. But it does have an impact on developers."
Based on results from preliminary testing, Adobe estimates the 64-bit version of Photoshop CS4 will give a performance boost of about eight percent to 12 percent compared with the 32-bit version.
Nack told ZDNet.com.au's sister site CNET News.com that Adobe expects 64-bit Photoshop to run on 64-bit XP, but only Vista will be supported, adding that 64-bit support doesn't mean a night-and-day performance improvement that Macs will miss out on.
"We fully expect that when we ship CS4, Mac users are going to be seeing performance improvements," Connor said.
Adobe had planned to move to 64 bit on Macs with CS4. But in June, Apple announced its technology plans at its Worldwide Developer Conference and that changed the situation for Adobe, said Nack.
Apple provides two technologies, Carbon and Cocoa, to help programmers take advantage of operating system services such as managing memory, fonts, or windows. Initially, Apple had planned to make both Carbon and Cocoa available in 64-bit incarnations, but Apple announced at the conference that only Cocoa would be.
Photoshop is written using Carbon, which dates from the earlier Mac OS 9 era and is better suited to cross-platform programming; Cocoa, like the newer Mac OS X, dates back to Jobs' previous company, Nextstep.
"When they chose not to do Carbon 64, we had to reevaluate our road map for getting there," Nack said. Adobe immediately assigned new programmers to the Cocoa switch "so we could make this transition as fast as possible, but as the saying goes, nine women can't make a baby in a month. You can only proceed at a certain pace," he said.
The Carbon-to-Cocoa switch was simply too massive to push back CS4 for just a couple months, he added.
"No one — Apple, Adobe, Microsoft — has attempted to move an application the size of Photoshop from Carbon to Cocoa," Nack said.
