I mean I understand that. However in the video they mention that 36TF is going to be rare, so I was still going with 33TF for most use cases. I guess I was asking is it really 33/36TF and the answer is no, it's 18.
No, it's 33/36.
RDNA 3 uses a double-issue instruction system for its shaders, or something like that (I'd have to go back and look at the actual white paper to fully remember), but it basically means shader performance is theoretically double compared to RDNA 2.
It's kind of like how Nvidia swapped from 64 FP32 + 64 INT32 on Turing, to 64 FP32 + 64 Hybrid FP32/INT 32 on Ampere, where theoretically in clock cycles with no INT required, Ampere has 128 FP32 cores versus 64 in Turing.
Now, in the real world, that's not really going to be what happens. The 3080 technically has 2x the cores of a 2080 Ti at similar clocks, but only 30-35% better real-world performance.
RDNA 2 to RDNA 3 is kind of similar, the 7800 XT with 60 CU's often performs within the general vicinity of the 6800 XT with 72 CU's, so the double-issue system is doing SOMETHING, but it's just not actually a 2x gain.