I have 4090 and M1 Max 64GB. 4090 is far superior on Llama 2.
70B in particular is indeed a significant compromise on the 4090, but not as much as you'd think. 34B and down though, I think Nvidia is unquestionably king.
I'm no expert, but to me that sounds like a recipe for bad performance. Does a 70B model in 2-bit really outperform a smaller-but-less-quantised model?
I woukd say 34B is the performance sweetspot, yeah. There was a long period where allow we had in the 33B range was llamav1, but now we have Yi and Codellamav2 (among others).