This is a more or less empty scene after entering playmode and for the first ~ minute the fps is extremly low and then jumps to 100FPS
This is what I have captured from the profiler CPU wise.
SetPass Calls: 5 Draw Calls: 5 Batches: 5 Triangles: 40 Vertices: 80
(Dynamic Batching) Batched Draw Calls: 0 Batches: 0 Triangles: 0 Vertices: 0 Time: 0,00ms
(Static Batching) Batched Draw Calls: 0 Batches: 0 Triangles: 0 Vertices: 0
(Instancing) Batched Draw Calls: 0 Batches: 0 Triangles: 0 Vertices: 0
Used Textures: 4 / 16.3 MB
Render Textures: 23 / 59.4 MB
Render Textures Changes: 0
Used Buffers: 239 / 1.1 MB
Vertex Buffer Upload In Frame: 0 / 0 B
Index Buffer Upload In Frame: 0 / 0 B
Shadow Casters: 0
Total Used Memory: 0.96 GB GC: 116.9 MB Gfx: 45.1 MB Audio: 80.2 MB Video: 264 B Profiler: 324.6 MB
Total Reserved Memory: 1.39 GB GC: 172.7 MB Gfx: 45.1 MB Audio: 80.2 MB Video: 264 B Profiler: 417.0 MB
System Used Memory: 2.26 GB
Textures: 1076 / 145.5 MB
Meshes: 127 / 1.0 MB
Materials: 130 / 225.9 KB
AnimationClips: 0 / 0 B
Asset Count: 9846
Game Object Count: 178
Scene Object Count: 1485
Object Count: 11331
GC Allocation In Frame: 4851 / 0.6 MB
Active Dynamic: 0
Active Kinematic: 0
Static Colliders: 0
Rigidbody: 0
Trigger Overlaps: 0
Active Constraints: 0
Contacts: 0
Total CPU: 0.09ms
Light Probe: 0.00ms
Setup: 0.00ms
Environment: 0.00ms
Input Lighting: 0.03ms
Systems: 0.00ms
Solve Tasks: 0.03ms
Dynamic Objects: 0.02ms
Time Between Updates: 206.04ms
Other Commands: 0.00ms
Blocked Command Write: 0.00ms
Blocked Buffer Writes: 0
Total Light Probes: 0
Solved Light Probes: 0
Probe Sets: 0
Systems: 0
Pending Material GPU Renders: 0
Pending Material Updates: 0