Hello, I’m experiencing an issue where my 5.6 project’s system memory usage spikes from 1,300 MB to 16,000 MB after being left running in the background for 24 hours post-packaging. Should this be considered a memory leak? I’ve been debugging for several days now, but I still haven’t been able to identify the cause.
OS: Windows 11
UE : 5.6 ver
2026-04-21 repost (KB → MB)
Still lumen HW Ray Tracing makes memory leak at the background + minimize Packaging Instance..
It’s unlikely this alone would be considered a true memory leak, at least based on the numbers you shared.
An increase from ~1.3 MB to ~16 MB over 24 hours is relatively small, especially on Windows 11. A real memory leak typically shows continuous, unbounded growth that eventually leads to performance degradation or crashes. What you’re seeing could instead be normal behavior from background systems such as caching, asset streaming, or delayed garbage collection.
A few things worth checking:
Memory trend over time: Does it keep increasing past 16 MB, or does it stabilize? If it plateaus, it’s probably not a leak.
Garbage Collection: Unreal’s GC doesn’t always run aggressively in the background. You can try forcing GC (gc command) and see if memory drops.
Subsystem activity: Systems like logging, async tasks, timers, or streaming managers can accumulate memory over long idle periods.
Packaging vs Editor: Since this happens post-packaging, make sure you’re testing in a Shipping build and not Development, as debugging tools can retain extra memory.
Stat commands: Use stat memory, stat UObject, and memreport -full to get a clearer breakdown of what’s growing.
External tools: Windows Task Manager or tools like VMMap can help confirm whether the growth is from committed memory, working set, or just cached pages.
If the memory continues to grow indefinitely, then it’s worth digging deeper into potential leaks (e.g., unreleased UObjects, dynamic allocations, or third-party plugins). Otherwise, a small increase like this over a long idle period is usually normal and not something to worry about.
If you can share a memreport snapshot before and after the 24-hour run, it would be much easier to pinpoint what’s actually increasing.
Finally,
HW RayTracing/GI/Reflection OFF is solved my memory leak issue!