diff --git a/examples/raytracer.psl b/examples/raytracer.psl
index 2f2a16b..4d80d0c 100644
--- a/examples/raytracer.psl
+++ b/examples/raytracer.psl
@@ -765,6 +765,11 @@ func make_default_scene() -> scene:
 
 const default_fovy = 2.0 * atan(0.5)
 
+// Measured performance (apple m1 pro, 128x128, 1024 spp):
+// 1 thread:  133s (~8us    per sample)
+// 4 threads:  35s (~8.25us per sample)
+// 8 threads:  18s (~8.5us  per sample)
+
 func main():
 	let scene = make_default_scene()