One frame takes several times longer than usual to compute, so the screen freezes for a moment.
Why A burst of skill effects, a mass spawn, or a full UI refresh all land in one frame → Effect The frame can’t finish within 16.7 ms and takes 50–300 ms → On screen The screen hitches, then everyone moves at once on the next frame
When crowds gather, During specific actions, Randomly
Owner
Primary owner Game team (Client development)
Game team action items
Split heavy work across several frames, find spiking frames with a profiler, cap the number of effects.
Ballpark numbers
At 60 FPS, one frame is 16.7 ms. A single frame over 50 ms is often enough to make players feel “it stuttered.”
On the graph
Random spikes · Frame time
Where to look
Record frame time (FrameTime) and the time the CPU and GPU spent on each frame (CPUBusy, GPUBusy) with PresentMon during play. On mobile, the slow sessions and slow rendering metrics in Android vitals
Confirmed if
Frame time, normally around 16.7 ms, jumps above 50 ms at the same moments as skill effects, mass spawns, or full UI refreshes, while ping stays the same
Ruled out if
Frame time steady but other characters hitch: points to the network side (e.g., “Missing or too-short interpolation buffer”). Spikes at regular intervals: check “Client garbage collection” first
Check with
The player’s own environment
Sources
Slow renderingAndroid (Google) To hit 60 FPS, a frame must render within 16 ms; late frames get skipped and show up as stutter (jank)
Slow Sessions (games only)Android (Google) Android vitals counts a game frame as slow when it takes longer than 50 ms (20 FPS) or 34 ms (30 FPS)