For me this morning Bart, that's not how math works (LOL)...100% of 100 is 100. So if something is 100% FASTER it's 2x the base value. 100% performance increase = 2x performance. What the OP actually wants, no idea....
If this type of scenario where the performance is so different, I'd be hesitant to use raw fps
One link, same data and CPU (below). I can't help the 4090 would be CPU limited if he buys it. We have to run with what we have and not make concessions for higher resolution, different settings, and faster CPUs.............
If you combine the two, it is 1.33 * 1.85 = 2.46x the speed of 1080 Ti.
Ok... then what about this page 2560x1440?
The NVIDIA GeForce RTX 4090 Founders Edition offers huge gains over its predecessors. It's the first graphics card to get you 4K 60 FPS with ray tracing enabled, and upscaling disabled. Do you prefer 120 FPS instead of 60? Just turn on DLSS 3.
www.techpowerup.com
2080 Ti averages ~105 FPS.... the 4090 averages ~200 FPS. 95 FPS faster. 95 against 105 is not 100%/2x, right?
EDIT: IF that's true above, and we know a 2080Ti isn't 100%/2x faster than a 1080Ti, how does that math work????
EDIT2: Did TPU mix data... what's this??
"Based on TPU review data: "Performance Summary" at 1920x1080, 4K for 2080 Ti and faster."
So, that chart that shows the 4090 is running at 4K, yet the 1080Ti is 1080p? Whaaaaaaaaaaaaa?