Performance lag on Blender Viewport & Screen Recording App when using HiDPI

[ryadhiprasetya]

I’m experiencing noticeable performance lag when using BetterDisplay HiDPI on my external monitor.

Setup

• MacBook Air M1, 8GB RAM
• macOS Sequoia
• Xiaomi A27Qi, 2560 × 1440
• BetterDisplay HiDPI: 2560 × 1440

Issue

When using the 2560 × 1440 HiDPI mode, Blender’s viewport becomes noticeably less smooth.

When I start screen recording using either OBS or QuickTime, the lag becomes significantly worse.

For comparison, when I disable HiDPI and use the normal 2560 × 1440 resolution, Blender is noticeably smoother, including while screen recording.

Is this expected behavior with HiDPI, and is there a way to reduce the performance impact while keeping the benefits of HiDPI?

[waydabber]

Yes, this is expected, as with HiDPI the system needs to move 4x as many pixels. The performance hit is real for real-time 3D rendering, especially on lower-end systems.

[waydabber]

Note: Blender may have an option to change the viewport rendering resolution - if there is such an option, set it to 50%. The extra pixels don't really show up on a 27" QHD display driven at native-equivalent HiDPI anyway, so the quality should not degrade by this.