1A per USB port may not be enough to run them at 500
The Sidehack USB hub provides up to 6A per port (shared between two ports)
Its a 120W hub with 10 ports, im only populating 3 ports for F + cooling fan. they are pretty steady at 550Mhz when a single hub is plugged to PC but as soon as i plug in a second hub to PC, the frequencies begin to flutter & the Fs on the 2nd hub would go past 300Mhz while affecting the Fs on the first Hub causing it to drop also ...
See below:
0: GSF 10050552: BM1397:01+ 550.00MHz T:550 P:550 (23:12) | 100% WU:100% | 355.2G / 356.1Gh/s WU:4974.9/m 1: GSF 10050555: BM1397:01+ 550.00MHz T:550 P:550 (24:12) | 100% WU:100% | 346.5G / 356.0Gh/s WU:4973.4/m
2: GSF 10050558: BM1397:01+ 550.00MHz T:550 P:550 (23:12) | 100% WU:100% | 328.3G / 353.9Gh/s WU:4943.6/m