The warning is fixed, the right GPU is selected - and your 4K timeline still plays like a slideshow. That is not the same problem. Here are the settings that decide playback smoothness once the GPU itself is healthy.
Fixing the GPU configuration gives Resolve its full strength, but a single graphics card still has a finite amount of strength. A 4K timeline stacked with noise-heavy footage, effects and colour nodes can exceed any one card in real time. Editors bridge that gap with playback settings - and understanding them matters more than another hour of driver reinstalls. Work through these in order; each one trades a little on-screen sharpness during editing for a lot of smoothness, and none of them touch your final export quality.
In the viewer options (the menu at the top of the timeline viewer) set Timeline Playback Resolution to Half, and for very heavy timelines Quarter. Resolve then processes a smaller picture while you edit - cuts, timing and sound are all judged at full accuracy, only the preview is lighter. Your rendered output still uses the full timeline resolution. This single setting is the fastest honest win for stuttering 4K playback.
Proxies are small stand-in copies of your footage that Resolve edits with instead of the originals:
Camera originals in H.264, H.265 or RAW formats are built for storage, not editing; making the CPU and GPU decode them live is the most common hidden cause of 'slow playback on a good PC'. Proxies remove that decode burden entirely.
Optimised media is the older sibling of proxies - Resolve creates easier-to-play versions of clips inside the project. Render Cache goes further: with the Playback menu's Render Cache set to Smart, Resolve pre-renders effects-heavy sections in the background (watch for the thin red line above the timeline turning blue). Both live on disk, so point your cache at a fast SSD in Preferences, then System, then Media Storage - a cache on a nearly-full slow drive causes as many problems as it solves.
First, GPU memory: if playback dies with a GPU Memory Full error rather than mere stuttering, your card's VRAM is the ceiling - lower playback resolution, split complex node trees, and accept that very large frames plus heavy Fusion work simply want a bigger card. Second, effects load: noise reduction and some Resolve FX are meant to be rendered or cached, not played live, on any realistic hardware. Smooth editing is a workflow, not a single switch - and now your GPU warning is fixed, it is a workflow fully under your control.
With the GPU fix from the video in place, these playback settings are the second half of the job - the video's channel has full guides on proxy workflows too.
▶️ Watch Full VideoBecause the warning and the choppiness are different problems. The warning meant the GPU was misconfigured; choppiness means the timeline's real-time load exceeds one card - usually hard-to-decode footage or heavy effects. Playback resolution, proxies and render cache are the correct tools for it.
No. Playback resolution only affects the editing preview, and proxy mode swaps back to the full original files for rendering as long as the originals are still available. Your export is always made from the full-resolution media at the timeline's delivery settings.
Your graphics card ran out of video memory mid-task. Lower the timeline playback resolution, reduce simultaneous effects, close other GPU-hungry apps, and let the render cache work in smaller stretches. On very high-resolution or Fusion-heavy projects it can be a genuine sign the card is too small for the job.