The mystery of Apple M3 Ultra GPU performance

The press release of M3 Ultra claimed that its GPU performance is 2.6x of M1 Ultra.

https://www.reddit.com/r/LocalLLaMA/comments/1j4jpij/comment/mgg62l5/?context=3

I thought the 2.6x gain was due to doubling of shader per core. But some people pointed out that the gain can be attributed to the existence of ray tracing cores in M3 that is not in M1/M2.

To investigate the impact of ray tracing, I looked up the previous press release for M3.

https://www.apple.com/hk/en/newsroom/2023/10/apple-unveils-m3-m3-pro-and-m3-max-the-most-advanced-chips-for-a-personal-computer/

It says M3 Max is 1.5x M1 Max, M3 Pro is 1.4x M1 Pro and M3 is 1.65x M1. Then constructed this table:

M3 vs M1 Ultra Max Pro Vanilla
GPU Gain 2.6x 1.5x 1.4x 1.65x
M3 FP16 57.344 28.672 12.9024 7.168
M1 FP16 42.5984 21.2992 10.6496 5.3248
FP16 Gain 1.3462x 1.3462x 1.2132x 1.3462x
RT Gain 1.9314x 1.1142x 1.154x 1.2257x

If I assume no doubling of shader per core, then M3 Ultra FP16 is 57.344. I assume the overall GPU gain is the product of FP16 and RT. Then I calculated the RT Gain and noticed that M3 Ultra's RT Gain is very different from the others. If I assume M3 Ultra FP16 is 114.688, then RT Gain is 0.9657x. This is closer to the other RT Gain but still a bit off.

So the conclusion is that RT cores probably doesn't explain this 2.6x gain fully. Any ray tracing experts here that can share their opinion?