Xbox One’s 32 MB ESRAM is said to be the main culprit behind multiplatform games running at lower resolution as compared to Playstation 4 and many developers openly admitted this. Recently during a livestreamed presentation at Build Xbox One team Partner Development Head “Frank Savage” explained in detail the exact working of controversial Xbox One’s ESRAM and also stated that with the help of it developers can touch glorious 1080p/60 FPS resolution mark.
Frank explained: “ESRAM is dedicated RAM, it’s 32 megabytes, it sits right next to the GPU, in fact it’s on the other side of the GPU from the buses that talk to the rest of the system, so the GPU is the only thing that can see this memory.”
“And what it does is that it gives you very very high bandwidth output, and read capability from the GPU as well. This is useful because in a lot of cases, especially when we have as large content as we have today and five gigabytes that could potentially be touched to render something, anything that we can move to memory that has a bandwidth that’s on the order of 2 to 10 x faster than the regular system memory is gonna be a huge win.”
“So this is where you put things that you gonna read a lot like a shadow map, put things that you draw to a lot, like your back buffer… We have resource creation settings that allow you to put things into there, and don’t have to all reside in the ESRAM, there can be pieces of it that can reside in regular memory as well. So for example if I’m a racing game, and I know that the top third of my screen is usually sky and that sky doesn’t get touched very much, great, let’s leave that in regular memory, but with the fast memory down here we’re gonna draw the cars. This works practically for any D3D resource there is, buffers, textures of any flavors… There’s no CPU access here, because the CPU can’t see it, and it’s gotta get through the GPU to get to it, and we didn’t enable that.”
“So the last thing you have to do to get it all composited up is to get it copied over to main memory. That copy over to main memory is really fast, and it doesn’t use any CPU or GPU time either, because we have DNA engines that actually do that for you in the console. This is how you get to 1080p, this is how you run at 60 frames per second… period, if you’re bottlenecked by graphics.”
The explanation from Savage is really intriguing, but only time will tell what all things developers can achieve with it on Xbox One. How many of you agree with the explanation issued by Savage on controversial “Xbox One’s ESRAM”? Share your views with us in the comment section below.