4.5 GB is the baseline guaranteed amount, while an extra gig of “flexible” memory can be used.
A development source recently spoke to The Digital Foundry to reveal some interesting details about the PlayStation 4’s oft-publicized 8 GB DDR5 RAM. Whereas Microsoft’s Xbox One would be allocating about 3 GB of RAM for the OS, leaving 5 GB for game developers to use, it was always assumed that the PS4 would allocate 1 GB for its OS, with the remaining 7 GB used in development.
However, it seems that guaranteed baseline RAM is 4.5 GB dedicated specifically to games while 1 GB, which is used for the OS, is classified as “flexible” memory which can also be utilized for development. And that’s if the OS isn’t doing anything with it at the time.
The current “Game Memory Budget Mode” on dev kits allows for normal and large modes in the debug settings. The former allows 4.5 GB off the bat, while the latter allows for 5.25 GB but is available only for application development. Either way you look at it, the Xbox One and PS4 are a lot more similar than it first seemed. Nonetheless, in terms of GPU power and type of RAM, the PS4 can still claim to be ahead of the Xbox One…or can it?
Given that it was a source that revealed all and not an official announcement or confirmation based on public testing of the console, there’s still room to be skeptical. Stay tuned for more details.