That's true but 3.5x in Ray Tracing feels too far fetched. I think 2.5x in Raster makes more sense with all of it's Infinity Cache, 15360 Stream processors (6900XT has 5120), New MCM design, TSMC's 5nm and etc.
From what I understood about the rumours, no one really knows the RT performance of RDNA 3.
PC Specs: CPU: 7800X3D || GPU: Strix 4090 || RAM: 32GB DDR5 6000 || Main SSD: WD 2TB SN850