PlayStation 4 games will utilise a mix of Direct Memory and Flexible Memory, Sony Computer Entertainment has confirmed.
Last week it was reported that PS4 games will be restricted to a guaranteed 4.5GB of GDDR5 memory, with a further 1GB made available through Flexible Memory freed up when not required by the console's operating system – this is only partially accurate, Sony has confirmed.
A Sony statement given to Digital Foundry reads:
We would like to clear up a misunderstanding regarding our 'direct' and 'flexible' memory systems. The article states that 'flexible' memory is borrowed from the OS, and must be returned when requested - that's not actually the case.
The actual true distinction is that:
- "Direct Memory" is memory allocated under the traditional video game model, so the game controls all aspects of its allocation
- "Flexible Memory" is memory managed by the PS4 OS on the game's behalf, and allows games to use some very nice FreeBSD virtual memory functionality. However this memory is 100 per cent the game's memory, and is never used by the OS, and as it is the game's memory it should be easy for every developer to use it.
Sony added that is has "no comment to make on the amount of memory reserved by the system or what it is used for."
It's believed that the 4.5GB of Direct Memory is an accurate figure, with 1GB of Flexible Memory split between 512MB of on-chip RAM and 512MB being paged much like a Windows swap file.
PS4 will launch this holiday season, priced £349.
Source: Digital Foundry