Let’s assume I’m a games developer and I’m in the middle of creating a game for the PS4. There are reports that Mantle is similar to the Playstation 4’s API. Since the PS4 uses the GCN technology, Is it relatively easy for me to port my game to the PC from PS4 using the Mantle technology, particularly if I were using an engine like Frostbite 3 or say Unreal?
Robert Hallock: We’ve designed to make Mantle’s programming model to be similar to what game developers are already creating for other platforms. Of course “ease” is relative to application complexity, but we do try to make it as easy as possible with robust error detection tools, healthy documentation and robust support from the AMD brains behind Mantle. All of the game developers currently working with Mantle have, again, been quite pleased with our efforts in this category.
I, along with many others in the industry feel it was a great move by AMD to allow both Nvidia and Intel owners the chance to use TressFX. Although a very different beast, could you clear up how Nvidia would be able implement Mantle if they wished to support it?
Robert Hallock: It wouldn’t be prudent of me to comment on behalf of other companies.
What were the factors prompting AMD to create the Mantle API? Was it simply a case of helping developers solve the major weaknesses of PC gaming architecture (the overhead) in preparation for the next generation of consoles and game engines?
Robert Hallock: Game developers did the rounds in the industry, asking all of the hardware vendors with a stake in graphics for a solution to make PCs more “console-like” with respect to hardware utilization efficiency and programming simplicity. They recognized that PC gaming could learn a lot from its siblings in the living room. Only AMD took these requests from the negotiation stage to the manpower and money phase, and Mantle was born! (MORE info can be found here on Mantle)
Did providing the main technology inside both Sony’s Playstation 4 and Microsoft’s Xbox One console influence the design of your future hardware, either in the discrete GPU or APUs?
Robert Hallock: I don’t work in AMD’s semi-custom business unit, so I couldn’t intelligently comment. (interviewers note – I’ve got an interview with the APU department lined up soon!)
With the release of the Radeon R9 290X, bandwidth was increased by changing to a 512-Bit Memory bus from 384 and also doubling the ROP count of the GPU, ratio wise that’s higher than the increase in Stream Processors. Do you find that the bottleneck of GPU’s is becoming more on ROP and local memory bandwidth (on the discrete GPU) or is everything fairly balanced? Additionally, what’s the ideal ROP, Texture Units and bandwidth ratio vs say 8 GCN cores (or 512 Stream Processors)?
Robert Hallock: GPU design is analogous to the game engine design question you previously posed. Everything does have to be balanced. You could throw fistfuls of render backends at a GPU, but if your memory bandwidth is insufficient, then that hardware is wasted. And vice versa, of course.
I think it can best be explained by working backwards, asking yourself: “What performance and resolution target do I want to hit?” Then you build a core out on paper that, by your mathematical models, would yield performance roughly equivalent to your target. Then you build it!
For 512 CUs, then I would say: 32 texture units, 16 ROPs and a 128-bit bus.
How do you feel Valve’s SteamOS will fit into the grand scheme of PC gaming? Valve have said that they’ve gotten better performance with their games on SteamOS than Windows. Will AMD support Linux Gaming and SteamOS with Mantle and other technologies in the future?
Robert Hallock: SteamOS’ ultimate position in the PC gaming ecosystem is anyone’s guess, but we are enthusiastic about Steam Machines and their open ecosystem approach to gaming. With respect to Mantle, we’re evaluating how it might be implemented, along with how and when Mantle for Steam OS should be rolled into our development plan. For now we’re focused on OpenGL as the delivery platform for Linux.
You can see other evidence of our efforts in Linux with our contributions to the 3.11 and 3.12 kernels, or iBuyPower’s recent announcement of AMD-based Steam Machines.
AMD seem to be in a great position right now for unifying games development, with your CPU, APU and GPU’s being used in PC’s and next gen consoles. Developers enjoying low level coding with Mantle, and other technologies such as TrueAudio and TressFX. Can you speak a little of your vision of games development, both on PC and consoles?
Robert Hallock: We’re tremendously proud of the continuum we’ve built in the gaming ecosystem. Game developers have already begun to leverage the commonalities, such as Crystal Dynamics’ recent decision to bring TressFX Hair to life for all platforms with the Tomb Raider Definitive Edition. We hope dividends will continue to be paid in this fashion for years to come for all platforms that we address.
Regarding TressFX, recently you’ve updated it to simulate more than just hair, for example grass and fur (which is very impressive tech might I add), and reduced the overhead associated with running it. Can you tell us if you’re planning to use a version of hardware Physics for smoke and debris?
Robert Hallock: I cannot speculate on unannounced technologies.
Could you give us your current thoughts on the state of the PC market? It seems that with the next generation of consoles using X86 based CPU’s, and more unified development, the PC is hugely benefiting.
Robert Hallock: PC gaming is alive and healthy. We revealed in Hawaii, with the launch of the AMD Radeon™ R9 and R7 Series, that enthusiast PC hardware is growing by $1 billion year over year through 2016. It’s a fabulous time to be a gamer! But, then again, when hasn’t it been awesome to be a gamer?
How do you see the progression of CPU’s, specifically for the desktop (gaming) PC developing over the next 3 to 5 years?
Robert Hallock: I’m afraid that I cannot reasonably answer this question, as I don’t work in the CPU division at AMD. (Interviewer’s note: I’ve got another interview lined up where I’ll ask this and much more!)
Tomorrow or the day after will be another part of the interview. Robert came back to me with another load of answers at the last minute.
So that’s the end of part one of our interview with Technical Communications, Desktop Gaming & Graphics at AMD ,Robert Hallock and AMD as a whole. I’d like to extend my thanks to AMD for the interview, and I (along with no doubt many readers) are looking forward to the next part of the interview. So stay tuned, and hopefully you’ll join in for the tech analysis and for the second part of the interview right here at RedGamingTech!