Gadgetory

hey everyone this is Steve from gamers next astana and today we're talking about texture fill rates or texture filtering this is part of my efforts to define all of the GPU terminology that you run into when looking at new video cards and this is something I already wrote about you can hit the link in the annotations or description below if you're interested in learning more about texture fill rate for video purposes we're gonna look at the TM use very briefly the texture filtrate and more depth and then the core clock and how all three of these elements relate so when you're looking at say a gtx 980 and i'm using this only because i know the specs off the top of my head at gtx 980 has a TMU count of 128 a core clock of 11 26 megahertz and a texture filter array or fill rate of 144 point 1 Giga cycles per second so these are the numbers were interested in so the filter rate represents how many texels per second the GPU is capable of applying colors to of applying maps to of applying filtration processes to like bilinear trilinear at anisotropic filtering and its measured in Gigot axles per second so you've seen these settings in games before whether or not you understand them there's bilinear filtering try linear and nice and anisotropic and those filtering technologies effectively look at how an object is being drawn on your screen relative to the camera so you might not have an oblique view of an object an object might be like the floor in front of me or imagine a road in a racing game it's not an oblique angle to the camera it's an odd angle and it scales off into the distance like a vanishing point so what anisotropic filtering will do is help take something like the dots on the road that the lines the dotted lines and it will make sure that they they vanish into the distance in a smoother and more realistic sense without any filtering process at all in the old days what would happen is the texture would stretch because it's being applied to a square space rather than something like a trapezoidal space which makes more sense when you've got a road going like like that into the distance so the texture fill rate is what is being saturated when you're applying these technologies like anisotropic filtering it's also being saturated just when you're coloring a Texel because on the screen you've got several different objects you've got tons of different textures being drawn to each object and the video card needs to determine what color each individual dot on the screen should be at any given time based on your movements based on the camera angle based on lighting and shadows and all of this stuff and that's where we need a big pipe so at one forty four point one gig at Axel's per second that's one hundred and forty four billion texels per second that the GPU can process this sounds like a huge number and it is but it's maybe not quite so huge as you would think because you need to take into account that we're processing texels every second 60 times per second for an average of 60 fps which is sort of what we need as a playable framerate so if you've got a 4k screen just pretend for a second you've got a 4k screen that means you have 8.3 million pixels on your screen and that's a lot of pixels so the GPU it needs to draw these 60 times per second if you want a 60fps and it needs to apply filters to them and it's drawing off-screen pixels for other technologies so suddenly you're at 8.3 million times 60 which is approaching 500 billion texels or so per second that's a lot it's not 144 billion which is what our number is but it's still a lot and then you've got to apply a technology like anisotropic filtering for X for example so now you're filtering it four times and you're up to 2 billion texels per second and then we can draw off-screen objects this is new ish and gaming and that lets say off pretend off my camera there's a tower and it and below me there's a pool the pool is reflecting that tower and I can see the pool on my screen and I can see the reflection of the tower on the screen the GPU is taking these texels it's taking these textures it's taking all this data of the tower and it's applying it to the pool in front of me so it's drawing an off-screen object on screen and a reflection that consumed yet more of our pipe and that's why we need such a large pipe still you're basically never gonna approach anywhere close to 140 four billion texels per second even with the highest on games because you're gonna hit other bottlenecks before you get there and games just don't push that kind of throughput not yet anyway and these are things we said ten years ago when one Giga taxol seemed impossibly high but we surpassed that still though even in the worst case load scenario you're pushing one to four billion texels it's not even you know not even close to 144 but that is what texture fill rate is and it is calculated by taking the count of texture mapping units multiplied by the core clock of the GPU and then that gives you texture fill rate so in the case of a GTX 980 you've got 128 units times eleven twenty six megahertz megahertz and that is a measurement over time and then that gives you 144 Gigot axles per second because you can see the math on the screen that's how it does it so that's where TM use are relevant and each texture mapping unit is capable of processing one texel per purge cycle basically so you've got eleven twenty six megahertz those are cycles of the GPU and each TM you can process one texel so that's why it's 128 times the clock the core clock in the old days this wasn't always true in the view due to technology there were two texture mapping units which was a big deal and they weren't always as good as just strictly to texture my opinions because they had a rule each unit had to work on the same Texel or pixel at any given time so even though you've got two units they need to work on the same Texel and if the Texel only has one texture applied to it that means only one unit has a job to do the other one it's like hiring too many people to do the same job now in these days dual texturing was becoming a thing so there were often multiple textures applied to a single point in space where things are overlapping so then each unit could function on the same taxol because each unit is processing a different texture but it just goes to that the marketed rate or one 44.1 Gigot axles in this modern instance is not always representative of a real-world use case and this is also true with AMD where you've got a different amount of floating-point TM use from integer TM use so in a game that uses floating-point you've actually got fewer TM usable to you than in something some encoding the rendering task that uses integer units which will way outperform the FP unit so as far as texture fill rate and whether it's relevant the answer is yes with hesitation because all the texels on your screen which is every single 3d dot in space that has a texture applied to it needs to be filtered because the GPU needs to determine what color it should be needs to determine what sort of filtering is being applied in terms of bilinear and isotropic whatever how many times that taxol is being sampled that's what the four hex means it means each Texel is being sampled four times if you have 4x that's a lot that's producing a lot of load on the GPU suddenly and it samples it four times because it's trying to be more accurate and smoothing and determining colors and things like that and all these other factors so it's important but you're never gonna approach the numbers before you start hitting other bottlenecks like memory available or CPU bottlenecks or whatever really all kinds of other bada life's first that doesn't mean it's unimportant it just means that as gamers we don't utilize that pipes so heavily so that is texture fill rate and how TM use and core clock and everything to relate again link in the description below for the full article it might be a bit easier to follow with on this video because there are a lot of numbers and sometimes it's hard to follow on a video please like this video and subscribe to the page it helps a lot check out our new patreon page it's linked in the description below if you want to support these videos and upgrade the lighting or help get us to conventions or improve camera equipment check the patreon page it will help a lot even for a small support amount so that's that's this content I will be in CES next week see you all next time peace you