Chris: In the multi-vendor slide from APU13, you mention that Mantle isn’t tied to GCN. Right now, the API is GCN-specific. What would it take to expose its functionality on other GPUs then? Can this be done now, or would AMD need to make a decision to open it up? There’s a bullet that says forward-compatible, but can it also be made backward-compatible to prior/existing architectures?
Johan: Mantle requires a certain set of key functionality of the GPU, so it can’t be supported on older architectures before AMD’s GCN architecture. The focus right now for Mantle is to finish the implementation of the first version of it, and get it out together with a Mantle-based rendering back-end in Battlefield 4. This back-end will only be able to run on AMD’s GCN-based GPUs. Again, going forward I would like to see a future version of Mantle support GPUs from more vendors, and that would be a discussion that would have to happen between AMD, the other vendors, and us developers to figure out a way to make it happen.
Chris: Very cool. Okay, so I’ll just take us back to beginning; now that we've got Battlefield 4, and of course we want to do the best job possible of reflecting real-world performance on the hardware platforms we're testing. There's so much we can do with that on the single-player. I know you were always a big proponent of testing multi-player for the experience that's more persistent and probably more popular once everybody gets done. Is there a better way to do that yet in Battlefield 4? Do we have a solution for consistent multi-player testing?
Johan: Unfortunately not. We do have some internal tools that sort of records parts of the network stream that we use and then play that back and so you sort of play back multi-player footage, which is quite good. But it's not really packaged together in a sense that we can use it in the retail game unfortunately. It's also not fully true either because it's skipping quite a few things, actually, that you're doing in a full multi-player scenario there. Multi-player, unfortunately, as I say it’s rather chaotic, but it is the truer thing to see the real performance when you especially when it comes to CPU performance. GPU performance you can see pretty well with the single-player. But CPU performance is primarily multi-player. We don’t really have a great solution there unfortunately.
I think one of the best things one can do for benchmarking, but it's very tiresome for you guys, but that is to essentially play multi-player on the same level and play it similar ways.
Johan: Then spend quite a lot of time playing it actually, but it becomes, yeah, not a very exact science unfortunately.
Chris: Yeah, difficult to quantify for sure.
Chris: Johan, I again appreciate your time.
Johan: Yeah, no problem.
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