I did move the USB limit slider all the way to 100% and like I said 22fps was about the fastest it got. My desktop has 2 1TB SSDs and is an 8 core AMD 8350 that is overclocked. I dont think there is much more to say here about USB3 speed... I dont think you will get much over 20fps even at smaller ROI, I tested at 1920x1080 ROI and it was about the same speed. For really fast frame rates I think the new imx385 or the existing imx224 will remain the preferred cameras for lucky planetary imaging. 20fps however is fast enough for Lunar or Solar I would think... But ultimately the primary use of this new sensor is going to be DSOs
I hope to be able to do more live testing this weekend as Saturday night looks to be clear.