| Dark_Feanor said:
And as you pointed console memory bw are very high and devs try to feed as much as possible to the GPU. But the CPU problem claim is understandable: If the CPU is demanding to much bw that chunk will be unavailabe to the GPU as long as the CPU is bussy. And a lot of computation has to be done in the 33us back and forth CPU->GPU even if the GPU becomes idle it has to wait the CPU finish their tasks and free the memory. I don´t know if all the PS4 memory pool could be read/written at the same cicles, or how big the pipeline could get before CPU start starving. If I remember even Cerny said that that was the reason they considered ERAM for a long time into development, but decided for a big and fast GDDRAM. There are bootlenecks everywhere anywhere. Dosen´t matter how advanced is the archtecture. |
There is more to all this though... but no need to get into all that.
The simple reason why the game runs at 900p on both consoles is optimization. Or the lack of it there of. ESRAM does not give the XB1 any kinda of advantage over the PS4. But I will talk about that some other time. In truth, there is not a single thing hardware wise that the XB1 has that is better... well, except the higher clocked CPU.
The game was simply built primarily on the XB1. Plain and simple. They got the game running at 900p 30fps on the XB1 and are just going to (if they haven't already) do a very simple straight port to the PS4. It is easier porting to the PS4 from the XB1 than porting to the XB1 from the PS4. Basically, f you can get anything running on the XB1, then it will run with minimal effort on the PS4.
There is nothing wrong with them prioritizing XB1 development, if I were them its exactly what I would have done too. Its just that they didn't feel the need to have to deal with getting the PS4 version optimized, they figured 900p is good enough for everyone. Which is ok.... their excuse just wasn't true though.
