Movie Render Queue Long Sequence Memory Leak – Crashes After 2–3 Hours (UE5.6, 1080p, 64GB RAM)

Hi everyone,

I’m running into a persistent memory issue with Movie Render Queue when rendering long sequences in UE5.6.

Setup:

  • Unreal Engine 5.6
  • Resolution: 1080p
  • GPU: 16 GB VRAM
  • RAM: 64 GB
  • Output: EXR sequence (sometimes with Cryptomatte/multi-pass)
  • Renderer: Path Tracer
  • OS: Windows 10

Problem:
When I render long sequences (e.g. 1500–2000+ frames) via MRQ, memory usage starts around 50% of my RAM but keeps growing over time until the system runs out of memory and the editor crashes after ~2–3 hours. This happens even if the scene complexity is moderate.

Notes:

  • I have “Flush Grass Streaming” disabled.
  • I keep Texture Streaming enabled and avoid “Flush Streaming Managers”.
  • Warm-up frames are set (32).
  • I tried reducing Temporal/Spatial samples and disabling Cryptomatte, but the memory growth still occurs.
  • Splitting into smaller jobs via command line works fine (memory resets per segment), but I’d like to know if there’s a way to run the full sequence without manual segmentation.

Questions:

  1. Is this a known memory leak issue in MRQ for UE5.6?
  2. Are there additional settings or workarounds that can stop memory from continuously increasing?
  3. Any way to make MRQ automatically “flush” unused resources during a long render without restarting the process?

Thanks in advance for any tips or confirmations.

I found that Structured Buffer Memory was pretty high, even reached 250GB