In the wake of the resolution gate issue concerning Microsoft’s new console, the Xbox One’s ESRAM has taken quite a large amount of flak from consumers and critics. During a livestream presentation at Build, Xbox One Team Partner Development Lead Frank Savage attempted to explain just how the console’s ESRAM works and how beneficial it can be to developers to help reach 60 fps at 1080 native resolution.
The presentation titled, Understanding the Xbox One Game Platform Built on Windows, speaks about the console’s architecture and highlights advantages that developers can opt for.
Savage started by informing us that the Xbox One has 32 MB of high speed ESRAM, that sits right next to the GPU. The location makes it so that it’s the GPU alone which can “see this memory.”
According to the developer, this results in giving a “very very high bandwidth output, and read capability from the GPU as well.” By today’s standards where applications demand a high amount of bandwidth to render scenes, Xbox One’s ESRAM is perfectly capable of the challenge.
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.
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.
Savage continued saying that all of the composited material can be copied over to the main memory really fast and that it does not use any CPU or GPU resources. The reason is that the DNA engines do that instead.
…and hence according to the presentation that’s how you can cross the barrier and reach 1080p and 60 fps if “you’re bottlenecked by graphics.”
We’ll see if this helps developers with their titles in reaching the said mark.