DLSS, FSR and XeSS: how upscaling works and when to use it

Running a modern game at 4K is expensive. Upscaling is the trick that makes it affordable: the game draws fewer pixels, and a smart algorithm turns that smaller image into a full-resolution one. Done well, you get a large boost in FPS and a picture that looks close to native. Here is how it works and how to choose.

The basic idea

Instead of drawing every pixel of a 4K frame, the game renders internally at, say, 1440p, and then an upscaler enlarges it to 4K. Simple stretching would look blurry. Modern upscalers use information from several earlier frames, motion data and depth to rebuild detail that a plain stretch cannot.

The three main technologies

• DLSS is made by NVIDIA and works on GeForce RTX graphics cards. It uses dedicated AI hardware on the card, and it usually gives the best image quality of the three.
• FSR is made by AMD. It is open and works on a wide range of graphics cards, including those from other makers, and on some consoles and handhelds. Newer versions use temporal methods and are much better than the first release.
• XeSS is made by Intel. It works best on Intel Arc graphics cards, and a version also runs on other hardware, with lower quality there.

A game decides which of them it supports, so check the graphics menu. Some games offer all three.

What the quality modes mean

Most upscalers offer modes such as Quality, Balanced, Performance and sometimes Ultra Performance. They differ in how low the internal resolution is. For example, a Quality mode renders at about two thirds of the output resolution on each side, while Performance renders at about half.

• Quality gives the best picture and a moderate gain.
• Balanced is a good default for most people.
• Performance gives a large gain and works best at high output resolutions such as 4K.
• Ultra Performance is for emergencies and for very demanding games or weaker hardware.

The higher your output resolution, the better lower modes look, because the upscaler has more to work with.

Frame generation is a different feature

Some of these technologies also offer frame generation, which creates extra frames between the real ones to raise the displayed FPS. It is not the same thing as upscaling. It can make motion look smoother, but it does not lower input delay, and it can add a little. It works best when the game already runs at a decent frame rate, around 60 FPS or more, before you turn it on. In fast competitive games many players leave it off.

When to use upscaling

• When you want 4K or high refresh rates on a graphics card that cannot do it natively.
• When ray tracing makes a game too slow.
• On laptops and handhelds to save power and heat.

When to be careful

• At 1080p, lower modes can look soft, so choose Quality or leave it off if you have spare performance.
• Fine details such as thin wires or fast particles can show small artifacts in some games.
• If your processor is the bottleneck, upscaling will not help much. See how to tell if you are CPU or GPU limited.

A simple way to choose

1. Set your screen's native resolution.
2. Pick the upscaler your hardware supports best.
3. Start with Quality. Check the FPS and the picture.
4. If you need more speed, move to Balanced, then Performance.
5. Turn frame generation on only if the base frame rate is already good and you want extra smoothness.

Upscaling is one of the best free upgrades in modern gaming. For the full list of ways to speed up a game, read how to raise FPS in any PC game.