Microsoft’s upcoming Xbox Series S (codenamed Lockhart) is going to target 1080p 60 FPS or in some cases 1440p 30FPS, as per sources. The Series S will be the cheaper sibling of the Series X and cost markedly less (some rumors say $200, but I don’t buy it).
As per Tom Warren, both the consoles will feature an identical CPU, an eight-core Zen 2 chip paired with a GPU with lower Compute Units and reduced frequencies compared to the Series X. Contrary to earlier reports, Lockhart won’t be a streaming console, just a more affordable option for gamers not too worried about the visual fidelity.

It’ll likely lack an optical drive though as a cost-cutting feature and be Digital Only. It’s not clear whether Sony will have a competitor for the Series S but chances that it won’t need it considering the vast library of exclusives. (househummus.com)
The Xbox Series S will be capable of running at both 1080p 60 FPS as well as 1440p 30 FPS and it’ll be up to the developers to opt for the desired resolution. It’ll be interesting to see how this pans out. While most gamers prefer a higher visual fidelity over quality, seeing that the Series S is targeted at folks who aren’t bothered much about the graphics, developers might stick to 1080p with higher frame rates.