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[Nathan Peterson]

Great points so far in this thread, but I want to be precise about one common misconception: Lumen isn’t really “software ray tracing” in the RT-core sense—it’s a hybrid voxel + screen-space + software raymarching system. It first builds a virtualized hexagonal voxel representation of the scene, then does a coarse diffuse pass over those voxels and refines with screen-space hits. The key architectural difference from hardware RT is that Lumen never does actual ray/geometry intersection in silicon; it’s approximating indirect light transport through acceleration structures it maintains in VRAM. That’s why it scales far more gracefully on non-RT hardware, but it also means you pay the cost in compute shader overhead and warmup frames. On my rig I’ve seen Lumen cost 8-15% FPS in a typical interior scene versus zero RT overhead, and that’s before you factor in the per-frame voxelization rebuild cost that spikes whenever geometry or lights move.

From a competitive gaming standpoint, the tradeoff is pretty decisively in Lumen’s favor, and here’s the practical reasoning: in fast-paced shooters, you’re playing on contrast, motion

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