So, what we do as the game accesses the Blu-ray disc, is we take any data that was accessed and we put it on the hard drive. And if then if there is idle time, we go ahead and copy the remaining data to the hard drive. And what that means is after an hour or two, the game is on the hard drive, and you have access, you have dramatically quicker loading And you have the ability to do some truly high-speed streaming.
Mark CernyIt's possible to do computing in the Cloud, PlayStation 4 can do computing in the Cloud. We do something today: Matchmaking is done in the Cloud and it works very well. If we think about things that don't work well... Trying to boost the quality of the graphics, that won't work well in the Cloud.
Mark CernyIf you look at the portion of the GPU available to compute throughout the frame, it varies dramatically from instant to instant. For example, something like opaque shadow map rendering doesn't even use a pixel shader, it's entirely done by vertex shaders and the rasterization hardware - so graphics aren't using most of the 1.8 teraflops of ALU available in the CUs. Times like that during the game frame are an opportunity to say, 'Okay, all that compute you wanted to do, turn it up to 11 now.'
Mark CernySo, what we do as the game accesses the Blu-ray disc, is we take any data that was accessed and we put it on the hard drive. And if then if there is idle time, we go ahead and copy the remaining data to the hard drive. And what that means is after an hour or two, the game is on the hard drive, and you have access, you have dramatically quicker loading And you have the ability to do some truly high-speed streaming.
Mark CernyThe original AMD GCN architecture allowed for one source of graphics commands, and two sources of compute commands. For PS4, we've worked with AMD to increase the limit to 64 sources of compute commands - the idea is if you have some asynchronous compute you want to perform, you put commands in one of these 64 queues, and then there are multiple levels of arbitration in the hardware to determine what runs, how it runs, and when it runs, alongside the graphics that's in the system.
Mark Cerny