It doesn't seem to be 2x faster on AMD (but mandatory "bait for wenchmarks).
AMD ran a YouTube ad that claims it's a 30% performance improvement on RX 7000 series: https://youtube.com/shorts/BKzty6YdRNM
Of course it depends on the exact scenario, but in games it's already known AMD ray tracing performance is quite bad compared to Nvidia and Intel, so it's not surprising they're also slow in Blender.
