Today I am doing my routine iPhone > Finder backup, checked the transfer speed out and figured you guys may want to see:
iPhone 15 Pro Max 512GB
to
Mac Studio M1 Max base 512GB
with
ACASIS TB4 cable that came with TBU405 NVMe enclosure
macOS is still at Monterey 12.7 (as this is a mission critical machine so I am not risking it with Ventura and Sonoma yet)
According to System Profiler, the negotiated USB speed of the iPhone is 10Gbps.
The backup was quick, much faster than I ever remembered on previous iPhones as late as my other 13 Pro. You can tell from the iStat Menus graph, the writing speed to the Mac SSD means how much the iPhone is actually putting out, at 421MB/s (byte) is 3368Mbps (bit), so just 1/3rd of what is the theoretical speed. Granted backing up is more of a random access process than sequential, maybe transfer a single large file like a video can get better speed, but I can make do with 400MB/s for the rest.