The 256MB mark appears to be the minimum required for iOS 4 to multitask; while iPhone 3G owners can upgrade their phones to the new OS, they won't get multitasking.
By bumping up memory to 512MB, Apple leaves the door open to later expanding the iPhone 4's multitasking abilities. "The bigger issue is that this lets Apple release, maybe gradually, as it has always done with the iPhone, more functionality," said Vronko. "It can provide more [multitasking] APIs, maybe this year, maybe a year from now, that allow for more resource-hungry multitasking."
By this time in 2011, Vronko said, the difference between the iPhone 4's ability to multitask and that of the iPhone 3GS might be stark.
Half a gigabyte of system memory is now standard on top-tier smartphones from Apple's rivals, particularly those powered by Google 's Android operating system, Vronko pointed out. "In a sense, then, Apple is just catching up.
"But Apple can better manage the memory it has in the iPhone with its centralized memory management than can Android phones," Vronko claimed. The difference isn't huge -- Vronko estimated that iPhone apps require 10%-20% less memory than similar Android software -- but every little bit helps.
The confirmation of 512MB in the iPhone 4 contradicts evidence gleaned from photographs of prototypes leaked by the Gizmodo technology blog in April, and a Vietnamese site last month . In both instance, experts said that the next-generation iPhone would probably have only 256MB, the same as in the iPhone 3GS and the iPad.
After examining the photographs published by Gizmodo, Vronko said that there was a 50-50 chance that the final version of the new iPhone would have 512MB of system memory.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer or subscribe to Gregg's RSS feed . His e-mail address is firstname.lastname@example.org .
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