The combination of "maxed-out" and "starts" is kind of confusing, but I found the machine you're talking about - M5 Ultra with the 36-core CPU and 80-core GPU, 96 GB RAM, 1 TB SSD.

It has 6x the RAM, 2x the memory bandwidth and looks like it totally outclasses the RTX 4070 Ti SUPER. I did some searching and it looks like a close comparison would be the older M3 Ultra Mac Studio, although again, with a lot less RAM.