If the clips play at the correct speed on the timeline but appear to play in slow motion in the Source Viewer (or viewer before editing), it's usually one of a handful of things.
1. Source Viewer playback is dropping into low-performance mode
If Resolve can't decode the source media in real time, the Source Viewer may appear to play slower than real time.
Check:
Is the FPS indicator in the viewer below your project frame rate?
Does the timeline play smoothly while only the source clip is slow?
If so, try:
Playback → Proxy Handling → Prefer Proxies
Playback → Timeline Proxy Resolution → Half or Quarter
Generate optimized media for the source clips.
2. Clip frame rate mismatch
If the clip is, for example, 120 fps but Resolve is interpreting it differently, the Source Viewer may honor the original clip timing while the timeline uses a different interpretation.
Right-click the clip in the Media Pool:
Clip Attributes
Verify the Video Frame Rate
If it says something unexpected (e.g., 120 fps instead of 24/30), that may be the issue.
3. Cache or decode issue
Try:
Playback → Delete Render Cache → All
Restart Resolve.
If using H.265 10-bit, make sure hardware decoding is enabled.
4. Viewer isn't actually slow - maybe audio is disabled
Sometimes the viewer looks slow because frames are being displayed irregularly.
Turn on:
Workspace → Video Clean Feed (if applicable)
or simply watch the FPS indicator
5. Source tape vs Timeline
If you're in the Cut Page, Source Tape behaves differently than the Edit Page.
Does this happen in:
Edit Page?
Cut Page?
Color Page?