Sony may drop the Cell processor entirely in the PlayStation 4 in favor of a multi-core design, a report from Impress says. Having first considered a modified, upgraded version of the Cell processor that powers the PS3, the electronics giant is now believed considering a new processor design that would use a more direct design with multiple true processor cores. The switch if implemented would be a concession to developers, who have regularly complained that writing PS3 games is too difficult.
Development of this new path is in the early stages, and the actual features of the chip as well as the ultimate fate of Cell aren't known. Among its other options, Sony has mulled using Intel's Larrabee many-core design but hasn't put it in serious contention. Intel itself has delayed Larrabee indefinitely.
Compared to the three-core Xbox 360, the PS3's processor is technically much more complex as it uses just one full processor and 7 vector math units that need careful optimization and aren't always as useful as the main core. Although game features are often very similar between PS3 and Xbox titles, differences in performance have usually run against the PS3 as development troubles have occasionally led to noticeably slower performance.
Source: electronista