The good part of the teardown of a product is that we know much more about it than when looking only at the “official” specs tables. This is what happened exactly with the Playstation 4 showing a secondary processor and extra RAM chips that weren’t on any “official” specs list.
The secondary processor seems a low-power ARM one and the RAM is GDDR3 of 2 Gigabits (256 MB). The specific functions are yet to be discovered but experts think that both could be used to liberate the main processos and RAM from secondary task such as processes in the background (standby, downloads etc…).
According to vr-zone.com:
The newly revealed components include a low-power processor and 2 Gb (gigabits, not gigabytes) of GDDR3 SDRAM memory, stacking up to a total of 256MB of GDDR3 SDRAM. The auxiliary processor, which is known as “SCEI CXD90025G”, has been revealed as a low-power ARM solution–however its specific functions aren’t known yet.
There are many ways that the SCEI CXD90025G could compliment the PlayStation 4′s robust environment, and the gaming community has speculated a few interesting possibilities.
Since it’s a low-power processor, it’s likely to be associated with background functions like standby processes and downloads. Another guess is that it might be utilized for DRM, and some have suggested the ARM core processor allocates resources for the PS4′s automatic gameplay recording feature as well.
The unveiled processor might also help out with the PS4′s transitions from gaming to other apps, and is likely to aid in preserving game progress when switching to other apps or menus. It may also have something to do with saving the current state of the console in sleep mode–not to mention the downloads and updates during the system’s slumber.