How to Fix Multiplayer Lag Spikes from Garbage Collection

Multiplayer lag spikes from GC are local pauses, not the connection. Reducing allocations fixes them. Here is how.

How to fix it

1. Confirm it is GC, not the network

Profile to confirm the spikes coincide with garbage collection rather than network latency. Lag spikes on a good connection that align with GC are local pauses, not connection problems — different fix entirely.

2. Reduce allocations in network code

Serialization, message handling, and per-update networking often allocate. Reduce allocations there — reuse buffers, avoid boxing and temporary objects — since this code runs constantly and feeds the collector.

3. Pool networked objects and buffers

Pool spawned networked objects and reuse message buffers rather than allocating per message or spawn. This removes a steady allocation source that otherwise builds up to GC pauses felt as lag spikes.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.