There have been voices of concern around the internet about the 8 Gigabytes of GDRR5 RAM of the PS4 suffering from latency compared to to DDR3 RAM, but the console’s Lead Architect Mark Cerny isn’t particularly worried about that, as he explained as part of an in-depth interview on EuroGamer:
Latency in GDDR5 isn’t particularly higher than the latency in DDR3. On the GPU side… Of course, GPUs are designed to be extraordinarily latency tolerant so I can’t imagine that being much of a factor.
Cerny also explained that the choice of equipping the machine with 8 Gigabytes of RAM was a result of Sony taking in consideration feedback from developers, and that partners were very good at keeping it secret:
That was really a case where our developer-driven process worked. So we received feedback, we listened to the feedback, we altered the hardware as a result. As far as how late it was in the process, actually what you’re seeing there is just the developers were very, very good about keeping information confidential. As near as I can tell that all came from one rogue hacker, who wasn’t even disclosed by us, how managed to hack into a developer and extract both the Microsoft and Sony documentation.
One thing is for sure: from what we saw so far Cerny seems to definitely know what he’s doing (you can read his own explanation on the choice of RAM and bus combination for the PS4 here). We’ll have to see the results when the machine will actually be running in our own home theater, but for the moment things sound definitely promising.