2019 Mac Pro vs Mac Studio M1 Ultra: USB Speed Differs with many things, such as OWC Envoy Pro EX 8TB USB-C SSD
It is a curious fact that USB speed on the Apple Mac Studio is not necessarily better than older Intel-based Macs. No, I’m not referring to the front ports on the Apple Mac Studio M1 Max, which are only USB-C.
The top red and green lines are the 2019 Mac Pro. The USB-C bus is maxed-out or nearly so, which is exactly what you hope for.
The orange line and choppy green lines are the Apple Mac Studio M1 Ultra. The Mac Pro is 7.4% faster on writes, and 10% faster on reads, and with far more consistent performance. Same drive, same cable! This does not seem to be related to the drive, but to some foible of M1 Macs.
2019 Mac Pro: 1048/1032 write/read MB/sec
Mac Studio M1 Ultra: 976/936 write/read MB/sec
Vertical axis MB/sec. Horizontal axis shows % of volume capacity, e.g., 50% of 8TB volume is 4TB into capacity.