Why does my game drop frames even with good average FPS?

Because frame drops are individual spikes, frames that overran the budget, not a low average. A game can average 60 FPS while some frames spike, and those drops produce the hitches you feel even though the average looks great. Average FPS smooths over the variance. To find drops, look at frame-time variance and the worst frames, not the mean, which reveals the spiking work behind the drops.

How do I find what's causing frame drops?

Capture frame-time spikes and what the game was doing when each occurred, this pins each drop to its cause (an asset load, a GC pause, a burst of entities). Looking at frame-time variance rather than average FPS surfaces the drops, and the context around each spike identifies the spiking work. Then smooth it: stream loads off the main thread, reduce allocations to limit GC, spread entity bursts across frames, and pre-compile shaders.

What Causes Frame Drops?

Q: What causes frame drops?

Frame drops happen when an individual frame takes too long to render, exceeding its time budget (about 16ms for 60 FPS), because some work spiked. The causes are spikes of work: asset loading on the main thread, garbage-collection pauses, bursts of spawned entities or effects, physics or AI spikes, on-demand shader compilation, and sudden large allocations. Each overruns the frame when it happens, causing a visible dip. Frame drops are spikes, not a low average.

Quick answer: Frame drops happen when an individual frame takes too long, missing its time budget. The causes are spikes of work: asset loads, GC pauses, bursts of entities or effects, and physics or AI spikes, each overrunning a frame.

A frame drop is a single frame that took too long, a momentary dip that players see as a hitch. They come from specific spikes of work, not from your average frame rate. Here's what causes frame drops.

Spikes of Work That Overrun a Frame

If your game targets 60 FPS, each frame has about 16ms to render. A frame drop is a frame that exceeds that budget because some work spiked. The common spiking culprits:

Asset loading, loading something on the main thread, blocking the frame
Garbage-collection pauses, the runtime reclaiming memory, pausing the game briefly
Bursts of entities or effects, spawning many objects at once
Physics or AI spikes, a frame with unusually heavy simulation
Shader compilation, compiling a shader on demand the first time an effect appears
Sudden allocations, allocating a lot of memory in one frame

Each of these is work that exceeds the frame budget when it happens, overrunning the frame and causing a visible drop. Frame drops are spikes, not a low average.

Why Average FPS Hides Them

A game can average a fine frame rate and still drop frames constantly, because drops are individual spikes, not the average. Looking only at average FPS hides the drops players actually feel, you need to look at frame-time variance and the worst frames.

Bugnet's performance snapshots capture frame-time data from real sessions, so you can see the spikes and worst frames, not just the average. Looking at variance is what surfaces the frame drops an average conceals.

Finding and Fixing the Cause

Each frame drop traces to a spike of work, so finding the cause means identifying what spiked: capturing frame-time spikes and what the game was doing when they happened pins each drop to its cause. Then you smooth it, stream loads, reduce allocations, spread bursts across frames, pre-compile shaders.

Bugnet captures what the game was doing when frame times spiked, so you can target the real cause. So frame drops are caused by spikes of work overrunning a frame, asset loads, GC, bursts, and the fix is finding and smoothing the specific spiking work.

Frame drops are individual frames overrunning their budget from spikes of work, asset loads, GC pauses, entity bursts, physics/AI spikes. Average FPS hides them; look at frame-time variance to find and smooth the spikes.