Gadgetory

everyone I am joined by Raja Kaduri from AMD how's it going Raja it's going good it's good to have you here yeah thank you for hosting us we are in the am the offices in Sunnyvale and the last time we spoke was at the Macao event for Polaris right so since then a couple major things have happened in game technology the main one I guess to call attention to it would be doom with Vulcan being kind of like a seminal example mmm-hmm a Vulcan working so a major topic I wanted to ask you about was this idea of shader intrinsic function so we talked about this briefly in our 480 review since then it's become a lot more relevant can you give folks a top-level overview of shader intrinsic functions then we'll drill down into it yeah absolutely so kind of you know before we go specific on children 26 right you know the thing about first wall command dx12 is the reason we are very much excited about and you know we start with the whole mantle initiative for low-level API is it was around reducing the overhead of the API so that you don't need as many CPU cycles to you know push a frame to the GPU right and and also take advantage of all the courses that are available in the system and all the resources available in the system and that was the intent of those aps and and there was a basis for that that game consoles we're all based around kind of a very lower head low level APRs and if you look at a game console and compare it to a PC right if you just kind of as a game outright if I put myself as a gamer right you look at like can you pay $2.99 or $399 you get the whole box and you get the game and if you compare to the experience for the hour of game console to the experience for dollar of a PC game console is so far ahead you know that you get so much more I'm not saying that PC games don't look good right but they cost all right yeah no one's saying consoles or whatever's better than the other is just nuts per dollar it's just if you see experience but I call it so much better right and when you look at it and you know that bothered us all the time that you know it's the same hardware you have actually more hardware sitting on a PC and why is it that we can't give you know better experience per dollar can see right and when you kind of analyze it from a technical standpoint right all this kind of you know software infrastructure issues come about right one is the you know the API itself is I overhead you know the developer has more control of all the you know CPU cores and GPU on the console and not on the PC so the first step to that was hey can we do a lower head API on the PC which was kind of in a check with the x12 and welcome okay the next step so the API is one thing the next step is they are a whole bunch of hardware features right and instructions and all that are not exactly exposed through standard API so right like the experiment welcome okay so we had and we see that these features are leveraged by the developer on the console to get you know 10% 20% 30% I'm saying 2x performance and when they poured their game over to the PC they say ah I was doing this on the console and I know it's the same GCN architecture but I can't get access to this stuff right and so shader in turn six were one of those things that the you know the folks at Bethesda were using on they were doing some interesting things on the console and we said hey how do we give you access to the same thing on a PC so that's how you know that's kind of the motivation for the shade of intrinsic functions that we added to welcome where they could map their algorithms that they were doing on the console onto the PC I guess at a top level to it if I understand it right shader intrinsic functions sort of remove some abstraction layers to the hardware yes right so that is it going straight to machine code or when your motor dies I mean the compiler still has to kinda you know make sure that you know that everything is a you know legal proper program right that that's effective the hardware so compiler helps but yeah it's it's almost like inline assembly you know if you're an assembly program or you know you can inject in some versions of C compilers you can have inline assembly right say hey this this instruction just pass it on right you know don't do anything so it's kind of like that where you can insert these instructions right so so they can get as far at least as far as shader programs go near equivalent to whatever they can do on a on a game console right and and and it's cool that you know we we love welcome that allows us to extend the API to add these kind of features within our own schedule within our own control we don't have to go ask permission for everybody and you know other than you know getting the game developers to adopt it so that's so you're excited and what you will see us doing Steve from a game developer perspective is you'll see us kind of opening up a min the whole GPU open initiative and you know we can go more into that but was the idea was to make all the tools available on the PC right so if something is available in the hardware the developer needs to find a way to get to it so that was our goal right so it's not always easy to provide the console level access but we are trying you know you're opening up every every door we can right so I think you know if you drive the experience per dollar for the PC to be I it doesn't need to match console but it you know I think right now it's probably a factor of two or three easily factor of three off right sure so if it kind of gets closer you know PC gaming will try Vivaan more right I mean you know it's like it's a rich rich ecosystem and also things like we are happening and other stuff it just takes it to the next level right so I guess to take a step back and remind folks it's important to have this more direct access to the hardware we can look at I guess the the most probably cited aspect would be with direct x12 revoked in where you can move these draw calls directly to the GPU mm-hmm and eliminate that overhead on the cpu so speaking to that when looking at shader intrinsic functions with doom as an example what is sort of the immediate performance benefit that people should be looking for with Shaden so Sheldon yeah it's a really interesting question it could you know the lower head API is the benefit comes in application scenarios where your CPU bomb right right with children 26 it's actually a GPU feature it is like it helps in a GPU bound scenario right so my game is GPU bound you know whatever rendering I'm doing whatever drawing or anything then I need to find a better way to do the drawing right so I still want to accomplish drawing the same picture but can I do it in less number of cycles right you know less less number of instructions and that's where you know hey what is the hardware capable of you know can I do like you know combine these four operations together into kind of an interesting instruction that the hardware may have but I don't have control of that because I'm writing code at a high level and passing it through a compiler right so that's where shader intrinsics kick in is when I'm GPU bound which is a very common scenario especially if you do anything 1080p are about you know yeah your GPU Bond right so your CPU burned at lower resolutions but you know at 1080p and above you tend to become more GPU bound right where the shader intersects kick in and help you write which is part of the the immediate benefit there too is I feel like this generation of hardware more than ever we're seeing like there are X 480 as an example is a 200 250 dollar card but you're able to play pretty easily 1440p yes I write you know higher definition graphics yeah which is you know what's long time coming to town you know $200 level but yet it's an exciting place for a PC game all right that is it for part one of our interview with Raja Kaduri check back on Saturday the 22nd for part 2 where we talk about GPU open what it is how it compares to CUDA and we also talked about how software is more than 50% of the formula when talking about software and hardware and what they output for gaming BR and otherwise so check back for that on Saturday otherwise patreon links the post roll video as always subscribe for more and I'll see you all next time