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"We felt games needed a little more memory - about 10 per cent more - so we added a gigabyte of slow, conventional DRAM to the console," Cerny reveals, confirming that it's DDR3 in nature. "On a standard model, if you're switching between an application, such as Netflix, and a game, Netflix is still in system memory even when you're playing the game. We use that architecture because it allows for a very quick swap between applications. Nothing needs to be loaded, it's already in memory."
Some might say it's an extravagant use of the PS4's fast GDDR5 memory, so the extra DDR3 memory in the Pro is used to store non-critical apps, opening up more RAM for game developers.