Should I change the native resolution to get a different desktop size?

Usually, choose a scaled desktop size instead. Edit native panel pixel resolution describes the panel dimensions used for scaling calculations. It does not create a new physical timing or make the panel contain fewer pixels.

Keep the native dimensions matched to the actual panel unless you are correcting an incorrect report. To make interface elements larger or smaller, use Display Mode, flexible scaling or custom scaled resolutions.

For the underlying rendering method, see what flexible scaling and custom resolutions change.

If scaling choices suddenly disappear, inspect any saved native-size override before changing other settings. An accidentally tiny or incorrect native size can distort the generated resolution list. Correct it to the actual panel dimensions, then apply the configuration. This addresses an incorrect override. It does not bypass a rendering-size or refresh-rate limit.

The editor's current native-size row shows what macOS reports now. Typing pending dimensions does not immediately replace that value: system-configuration changes need Apply and any requested activation or restart. Even then, an arbitrary size is not a guarantee that the display and connection will provide a corresponding timing.

For example, a 5120 × 2160 panel can show a desktop with less logical space while retaining its physical output resolution. Relabeling it as 3840 × 1620 does not remove the need to scale an image to the panel's actual pixels or guarantee sharper text. See Resolution and text clarity.

Advertising a fictitious 8K native timing can make macOS expose a larger rendering surface, but it can also make the Mac send an 8K signal that a 4K panel cannot display. Exposing the desired HiDPI row is therefore not enough to establish a usable output mode. This is not a practical general workaround for a native HiDPI limit.

Check the monitor’s exact model specifications before trying to raise its native dimensions. A 2560 × 1080 panel does not become a 3440 × 1440 panel through a custom size or a higher-rated cable. A larger virtual desktop mirrored or streamed to it can provide more logical workspace, but the final image is still fitted to the physical pixels and may make text harder to read.

When the monitor is split between inputs

In hardware Picture-by-Picture (PBP) mode, each input drives only part of the panel. Match the dimensions to that input's area: for example, an equal vertical split of a 3840 × 2160 panel gives each input a 1920 × 2160 area, with an 8:9 aspect ratio. A normal 16:9 mode can leave unused space in that area. BenQ's PBP guidance describes selecting the matching input resolution on supported models.

If flexible scaling is using the full panel's proportions instead, first activate PBP on the monitor, then open System Configuration for the affected input. Enable Edit the system configuration of this display model and Edit native panel pixel resolution, enter the dimensions of that input's area, and Apply the configuration with any requested activation. With Enable flexible scaling turned on, these dimensions supply the aspect ratio used to generate scaled sizes. It cannot make the monitor accept an unsupported physical signal.

Check the configuration again when returning to single-input mode. A monitor may report different identification or modes in PBP, but do not assume every model automatically keeps separate settings for both states.

Use the connection mode list or EDID report when you need to inspect supported physical timings. See System Configuration for the native and default-size editors, and Display EDID for reported capabilities.