Purely for interest I tested this Sandisk 'Extreme pro USB 3.1' 128GB through a USB A - C adapter.
It was freshly formatted in ExFat and offered the hint on the screen that 9 minutes of 4K60 Prores Log could be recorded.
Viewed it on my macbook, only took a few seconds of video but as far as I can tell it worked fine, no visible dropped frames or stuttering.
The drive itself is maybe 5 years old already, and is a little above average as far as I know in terms of speed.
It was freshly formatted in ExFat and offered the hint on the screen that 9 minutes of 4K60 Prores Log could be recorded.
Viewed it on my macbook, only took a few seconds of video but as far as I can tell it worked fine, no visible dropped frames or stuttering.
The drive itself is maybe 5 years old already, and is a little above average as far as I know in terms of speed.