Render Cache: Overview - DaVinci Resolve Tutorial

- If the GPU status indicator turns red when you're dropping frames, even after you've enabled performance mode, then the render cache is a good option to consider. Now, if the render cache sounds like you're creating renders, that's exactly what you'll be doing. In Resolve land, the render cache is actually two different caching systems, the smart cache and the user cache. And you can only select one or the other. They don't both operate at the same time, but you can switch between them freely. Now, before we talk about the differences, let's talk about the similarities. The render cache is a per project setting. So what we're going to do is open up our project settings, shift nine. And in our master settings, if you scroll down, you're going to see a section called optimize media and render cache. So here are a bunch of our different options that we'll be coming back to throughout the rest of this chapter. What we're looking for for the render cache is this option here, render cache format, where they're using the user cache or the smart cache is render cache format tells Resolve what codec you want to render to. When it renders for you, what should it be rendering to? Ideally you want to select a codec that your computer can play back, but that's also at the quality level that you need to work with. So if you're editing, you're perfectly fine working, say ProRes 422, or ProRes LT. Or if you're wanting to use one of the DNX, HR codecs, feel free to use one of those. So let's say for now, we're just editing we don't need really high quality, so we can go to ProRes 422 that gives us a nice balance between quality and performance. The way the render cache works, once you turn it on, it'll automatically start caching. Now it'll either cache during playback and then the first playback will be stuttery. And then if you've chosen the right codec, the next time you play it back, it'll be buttery smooth, when Resolve plays back your cache renders. Resolve will also cache after your system has been inactive. In other words, while you're working, it stays out of the way when you stop to do something else, it'll take that idle time on the computer and start rendering. So how long does the computer have to sit idle before the render starts? That's what this option is down here, enable background caching after five seconds. So the way this works, if I click save, and now I come up and select under playback, one of these two settings, smart or user, Resolve doesn't start caching until one of two things happens, you either hit play and then it'll cache as you play down or you do nothing and then it'll cache after it waits in this case five seconds, and then it'll start caching for you automatically. Personally, I usually set this for one second because I like my background cache to work as quickly as possible and to take every moment of idle time that I can give it. The last setting that's common to both, the user cache and the smart cache, is the cache location. We're going to go ahead and set that cache location. Where should you set it to? Typically you would put it to your fastest hard drive or maybe your biggest hard drive. I like the fastest hard drive because that allows me to ensure I can use the highest quality cache codec that I need and I don't have to worry about playback speeds. So let's take a look. And what you're going to do is come down to the working folders. We're still here in our project settings, and you're going to see that there's a cache files location, go ahead, click browse. And then for me, that's going to be my raid. And what I'll do is I'll just pick the top level of the raid. I don't go down into any individual folders and click open, and there it goes. Now Resolve will create a cache folder for all of my caches on my main raid to get dropped into. Now sometimes when the render cache is rendering and then I go and I move the mouse, or I do something on the computer, sometimes it can take a moment for the render cache to stop what it's doing. And it slows me down, especially when it's rendering out fusion effects. So when that starts happening to me, then I go in and open up the preference and set my background cache setting from one second and I bump it up to three or four seconds so that it's not constantly interrupting me and then constantly slowing me down. And the next question you're probably ready to ask me is how do I turn on caching? Well, that's a good question. And that's what we're about to talk about next.