How to get the most out of your GPU subsampling to get the best image quality with your video games

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If we stick to a technical point of view, the experience that a video game offers us is conditioned by two parameters: its global image quality and the rate of images per second that its graphics engine gives us. The power of our graphics cards is limited, so gamers are often forced to moderate our demands in graphics to obtain an acceptable sustained frame rate at the resolution at which we enjoy our games.

If the GPU of our graphics card works to the limit of its possibilities at the resolution that we usually use, we will not have room to use the strategy that we are going to propose in this article. However, this is not the stage that all players find themselves in. Some of them have a graphics card capable of work without too much stress to the native resolution of your monitor, and, therefore, prepared to throw very high rates of images per second.

A user who has, for example, a monitor with a Full HD panel and a GeForce RTX 3070 or Radeon RX 6700 XT graphics card will be able to enjoy a very high frame rate per second at 1080p in a good part of their games. These are the circumstances in which it is worthwhile resort to undersampling they are able to perform most of the relatively modern graphics cards. And, as we will see in this article, its impact on image quality can be very beneficial.

Before we go any further, it’s important that we review what subsampling is and what it means for our GPU. This technique requires that the rendering of the images be performed at a higher resolution to which the graphics engine is going to deliver to our monitor. Of course, this implies that once each image has been generated, it must be compressed to adapt it to the final resolution at which we are going to play. What is surprising is that this process, known in English as downsampling, allows us to enjoy a significantly higher image quality in our games. We will check it later in this article.

Enabling downsampling is a no-brainer on AMD and NVIDIA graphics cards

Fortunately, take advantage of the subsampling that the GPU of our graphics card is capable of carrying out. It is very simple whether we have a Radeon or a GeForce. If our graphics hardware is from NVIDIA we will have to access the Control Panel that allows us to act on its operation by clicking with the right button of our mouse on an empty portion of our desktop and selecting the option NVIDIA Control Panel.

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Then we must click on the section 3D settings hosted in the drop-down list on the left side of the interface, and once we are inside it we will have to select the option Control 3D settings. Now we need to locate the parameter DSR factorsand when we have found it we will display it and we will mark all the resolutions with which the graphic engine of our games must work. As we have seen, these resolutions can be higher than the native definition of our monitor panel.

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We can easily ask the graphics engine of a game to perform the rendering of images at a higher resolution than the native one of our screen. This strategy is feasible because our graphics card knows the resolution of our monitor, so will process each image to adapt it to this last definition before giving it to you. This is precisely what subsampling consists of. One more note: we suggest that you set the parameter to 0 DSR smoothness. By default it is activated at 33%, although the ideal is that you try several options so that you can find the value that you like the most.

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Enable downsampling on an AMD graphics card it’s so simple how to do it in an NVIDIA. In this scenario, all we have to do is click with the right button of our mouse on an empty portion of the desktop and select the option AMD Software: Adrenaline Edition. Then we have to click on the tab Screenand, finally, we only have to activate the parameter virtual super resolution. This is all. From this moment we can already start using subsampling in all our games.

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Once we have indicated to the driver of our graphics card that it must carry out the rendering at a higher resolution than the native of our monitor, we will only have to enable this resolution from the setting options of each game. By doing so, the graphics engine will perform the rendering using that definition, and each frame will then be compressed to the appropriate final resolution before being delivered to our monitor.

The impact of undersampling on image quality is noticeable. and beneficial

Nothing we’ve seen so far would be interesting if it didn’t have a beneficial impact on the overall picture quality that our games offer us. But fortunately, has it. Of course, as we will see later, this technique also has a cost in the rate of images per second that we should not overlook.

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We have collected the following screenshots with ‘Cyberpunk 2077’, a title that clearly benefits from graphic subsampling. In these images we can see that serrated edges are smoother when images are rendered at 2160p and subsequently compressed to 1080p than when rendered directly at 1080p.

Testquality1

In the following zoomed-in crop of the screenshots above we can clearly see that 2160p rendering combined with post 1080p compression retrieve more detail than direct rendering at this latter resolution. In addition, the sharpness of the images is higher, and, as a bonus, this technique often manages to reduce flicker noticeably (flickering). In this crop of the capture we can see that the level of detail of the rear window of the car is higher in the image generated by subsampling.

Testquality2

In the following screenshot of this popular CD Projekt RED game, which, by the way, is more enjoyable now thanks to patches than when it hit stores, exactly the same thing happens as in the images we just analyzed: subsampling again at 1080p since rendering at 2160p manages to recover a higher level of detail and gives us smoother jagged edges, and therefore with less aliasing.

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In this enlarged crop of the captures that we just reviewed we can see more clearly than the image rendered at 2160p and later compressed to 1080p retrieve more detail than the one rendered directly at this latest resolution. The side of the chair the character is sitting in has a distinctly higher level of detail in the image to the right, which is the one rendered at 2160p and subsequently downsampled to 1080p.

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Downsampling comes at a cost: if resolution goes up, performance goes down

We anticipate it in the first lines of this article: this strategy is only attractive if the GPU of our graphics card feels comfortable facing the rendering of images at the resolution that we usually ask for and leaves us room to approach rendering at a higher definition without excessively penalizing the cadence of images per second that it gives us. In the following table we illustrate what impact downsampling to 1080p from 1440p and 2160p has on the FPS rate in ‘Cyberpunk 2077’ using a PC equipped with an AMD Ryzen 5 5600X processor and an AMD Radeon RX 6900 XT graphics card:

cyberpunk 2077

fps

rendered at 1080p

130

rendered at 1440p and scaled to 1080p

90

rendered at 2160p and scaled to 1080p

40

If we have powerful hardware, the best results will be obtained by rendering at 2160p and downsampling at 1440p or 1080p. We can also render at 1440p and downsample at 1080p. And even if we have an exceptionally powerful PC, we can consider rendering to a resolution higher than 2160p and subsample to this last definition. We have tested it, so that in the following table we have collected the frame rates per second that we have obtained in ‘Doom Eternal’ when using a Radeon RX 6900 XT and an Intel Core i9-10900K processor:

eternal doom

fps

rendered at 2160p

178

rendered at 5120 x 2880 and scaled to 2160p

100

rendered at 5760 x 3240 and scaled to 2160p

75

rendered at 7680 x 4320 and scaled to 2160p

42

Finally, in the third table we have collected the rates of images per second that we have obtained in ‘Wolfenstein: Youngblood’ using exactly the same hardware from the table above:

wolfenstein: youngblood

fps

rendered at 2160p

151

rendered at 5120 x 2880 and scaled to 2160p

90

rendered at 5760 x 3240 and scaled to 2160p

71

rendered at 7680 x 4320 and scaled to 2160p

40

Two more notes before concluding. NVIDIA’s DLSS and AMD’s FidelityFX Super Resolution (FSR) image reconstruction technologies can be combined with subsampling in which we have just investigated with the purpose of perceptibly increasing the rate of images per second that our graphics card delivers to us.

Nor should we overlook that subsampling increases the consumption of our graphics card due to the greater effort it must make to face rendering at a higher resolution. The Radeon RX 6900 XT that we have used in our tests uses around 60% of its resources when rendering at 1080p, but this figure increases up to 100% when doing it at 2160p and downsample to 1080p. In these circumstances the consumption of the PC increases by approximately 50 watts.

If we stick to a technical point of view, the experience that a video game offers us is conditioned by…

If we stick to a technical point of view, the experience that a video game offers us is conditioned by…

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