Cross-game chat isn't possible on PS3 due to RAM restrictions 

Sony Worldwide Studios president Shuhei Yoshida has explained why the oft-requested cross-game chat isn't possible on PS3, Turns out, the main reason has something to do with memory restrictions.

According to Yoshida PS3's RAM is used up when running games.

"Once a game gets RAM we never give it back," he told Eurogamer. "It's not possible to retrofit something like that after the fact. The game has to use its own memory to do [in-game voice chat].

"There's always voice chat in the game. But it's a part of a game feature. It's not a part of an OS feature. That's the reason in terms of the ability to have voice chat across different games."

PS Vita has more memory than PS3, 512MB of RAM and 128MB of V-RAM, compared to the console's 256MB of RAM and 256MB of video RAM. Ergo, the reason cross-game voice chat will be made available on the handheld.