I think it's too pessimistic to say it can't be done in real time on current GPUs. I think it should be possible to do reliable low latency readback with modern

I think it's too pessimistic to say it can't be done in real time on current GPUs. I think it should be possible to do reliable low latency readback with modern explicit graphics APIs. The harder problem is scheduling the audio work at high priority so it always finishes before the deadline, but this too has improved recently because VR compositors also have strict deadlines they must meet.