Got a simple project that simply spawns 100,000 unlit cubes and moves them in a random direction at constant velocity from the center of the screen. When the cube leaves the screen, it is destroyed and a new one is added to the center of the screen with a random velocity. The test runs fine in the editor: But when I build it, the framerate drops precipitously thanks to several frames worth of idle time between scripts and rendering: Any idea what might be causing this? Running Unity 2020.1.0b7.3556, using Hybrid Renderer V2, Burst 1.3.0-preview.9 (Current), Entities 0.10.0-preview.6, URP 9.0.0-preview.14 (Current), Hybrid Renderer 0.5.0-preview.6 (Current). Happy to post project.