You probably won’t be able to run Portal RTX. I’ll just get that out of the way upfront. Based on Steam’s latest hardware survey, I’d estimate that less than 10% of PCs can even run Portal RTX, and it’s closer to 4% if we’re talking about reasonable fps and resolution.
Portal RTX is the most demanding game I’ve tested, and can only be run with clever image reconstruction techniques and the fastest GPUs on the market today. Air tracking is hard work, but that’s how it is Portal RTX it takes advantage of ray tracing making it the next generation benchmark I’ve been waiting for.
Much more demanding than you think
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Portal RTX it’s a lot more demanding than you probably think. Even two years after launch, Cyberpunk 2077 is the most demanding game in my GPU benchmark suite, with ray tracing on and off. Even Metro Exodus Enhanced Edition, which uses fully global ray-traced lighting, is easier to control than it Cyberpunk 2077.
But Portal RTX taxes even more. For reference, you can see how the RTX 3070 fared with Nvidia’s Deep Learning Super Sampling (DLSS) set to Auto in Portal RTX under. In both Cyberpunk 2077 and Portal RTX, I used the same DLSS mode and the highest ray tracing quality preset.
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Portal RTX is a showcase for Nvidia’s next-generation graphics cards such as the RTX 4090, and in particular, the unique frame generation capabilities of these GPUs with DLSS 3. Even free frames, Portal RTX taxes the RTX 4080 much more than Cyberpunk 2077 works.
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Cyberpunk 2077 and Portal RTX could not be more different (technically and thematically), but it is a good illustration that Portal RTX perhaps the most challenging ray tracing game we’ve seen yet. Or at least, it’s the most challenging ray tracing game you could possibly play.
The question is why? Portal It’s 15 years old at this point, and even with updated elements and bouncing rays, it certainly can’t be more demanding than a dense, vibrant open world full of available ray-traced lighting. Cyberpunk 2077 (or countless other ray tracing games).
But it does, and there’s a good explanation why.
Why is Portal RTX so tiring
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Portal RTX it uses path tracing, which you can see Nvidia calls “full ray tracing”. That alone is not the reason Portal RTX is so demanding — it’s how Nvidia uses path tracking to track all the lights throughout the scene, as well as the shadows, reflections, and refractions those lights introduce.
Path tracking works by drawing a line from your camera. It travels in a straight line until it hits an object, bounces off, and continues on, eventually returning to the light source. Complications arise with the way different objects handle light. Part of that light is absorbed, other light is reflected, and part is refracted as refraction. Multiply this by each pixel and introduce more bounce (which Portal RTX does), and each frame becomes a complex sequence of mathematics that would make anyone dizzy.
Modern AAA games with ray tracing do not go through all these problems. The main example is Dying Light 2ray tracing lamp. It follows the rays where the lamp hits the surface and bounces them around the room, creating a soft glow in the dark areas where that illumination ends. Critically, it does not cast shadows or capture the color properties of objects the lamp interacts with.
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These limitations are necessary shortcuts for such a large game Dying Light 2. It uses ray tracing to improve certain features in the game. Portal RTX uses ray tracing to simulate light. Path tracking brings all the different aspects of light behavior in the environment under one roof, and ends up being much more demanding in the process.
Cyberpunk 2077 there are also many shortcuts. In ray-traced reflections, for example, the game calculates some data from typical screen space reflections (SSRs) depending on what is being reflected. In addition, post-process elements such as street fog do not transmit light further into the scene. This is not the case in Portal RTX, as you can see in the screenshot below. The blue cast from the corridor travels across the scene due to the soft fog and casts a blue light far beyond the corridor.
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Nvidia is no stranger to path tracking, shown by Quake II RTX demo. But Nvidia says Portal RTX includes four times more bounce than Quake II RTX and Minecraft RTX, which leads to a much more demanding (and physically more accurate) display of light.
Portal RTX it’s also built on Nvidia’s RTX Remix modding tool, which gives it access to features that weren’t available in previous tech demos and that we don’t see in typical ray-traced games. The first feature you’ll notice is RTX Direct Illumination (RTXDI), which allows any light in the scene to cast light and shadows on its path. In the scene below, I’ve highlighted four areas where RTXDI is in play: the yellow switch on the floor, the orange glow from the stairs, the red glow from the button, and the blue light from the window.
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The second is – brace yourself for it – Reservoir Spatio-Temporal Importance Resampling Global Illumination or ReSTIR GI. Nvidia has a research paper that goes into the nitty-gritty details, but in short ReSTIR GI takes multiple samples from critical light paths rather than tracking more paths. Despite what the performance above may suggest, this is actually more efficient and enabling Portal RTX track more bounce than you could.
put together, Portal RTX is a brief look at what might be possible in massive open world games like Cyberpunk 2077 and Dying Light 2 in the future. Shortcuts are needed, but it still serves to fully simulate the lights in the scene.
The challenge for next-generation GPUs
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When the RTX 4090 was announced, we criticized it for not having any games that pushed the GPU to its limits. Portal RTX is that game. Intensive ray tracing plays an important role, of course, but the 2007 edition has also been reworked with Physically Based Rendering (PBR) materials, new assets and a few fun easter eggs.
Portal RTX does not spoil the classics with excessively reflective surfaces and meaningless lighting like Quake II RTX did. It’s a beautiful game and the perfect excuse to revisit Aperture Laboratories. It’s just sad that so few of them will be able to lead the game.
With the RTX 3070, I averaged 1.9 frames per second (fps) with DLSS off at 1440p. Even with DLSS on, I was unable to reach 60 fps, and that was after I lowered the resolution to 1080p. There is no doubt Portal RTX it looks and runs great with the new RTX 40 series GPU and DLSS 3 in full swing, but you’ll need at least an RTX 3080 to push the game above 60fps with DLSS on.
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Unfortunately, that leaves the other GPUs out. Portal RTX it currently doesn’t work with Intel’s Arc A770 and A750, and AMD’s GPUs are too laggy in ray tracing to hold up (even at high end). Nvidia was kind enough to include a temporary upscaler for use with non-RTX GPUs, but that’s not the main issue you’re facing Portal RTX. How demanding the game is even with upscaling turned on.
The good news is that Portal RTX it’s an unlikely showcase of what the next generation looks and works like. We’ve had the same stack of demanding titles for several years now. Who would have thought that a quirky, two-hour puzzle game with a small streak of air would be the one to challenge the status quo?
This article is part of ReSpec – an ongoing bi-weekly column featuring discussions, tips and in-depth reports on the technology behind PC gaming.
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Source: newstars.edu.vn