The PS4 will limit game developers to only 4.5GB of its 8GB GDDR5 memory, internal development documents from Sony shown to Digital Foundry have revealed.

The reason for the cut in memory allocation is because of 3.5GB being reserved for the PS4 operating system, much in the same way the Xbox One locks off 3GB of its system memory for the OS.

A further 1GB of "flexible memory" is also believed to be offered to game makers when available from the OS, which could be utilised to boost elements of the game in some way.

It had previously been believed that the PS4 used only 512MB for its OS, leaving masses of memory for the games, but this may have been a relic of the earlier plans for only 4GB of system memory.

The extra memory allocated to the OS does, however, suggest that Sony has plans to offer a greater feature set than initially imagined, offering background processing and instant switching between apps and games - much in the way Xbox One promises.

Sources close to Sony have told Digital Foundry that Sony may also look to reduce the operating system's memory footprint and processor demands, freeing up extra resources to developers later down the line.

PS4 will launch this holiday season, priced £349.

Source: Digital Foundry