I want to play around with overclocking and see what can be done, as well as understand some more about amps/watts/volts.

I have the following hub: Sabrent 4-Port USB 3.0 Hub

I also got the following 5v-4A wall-wart: Sabrent 5V 4A 100V-240V to DC Power Adapter

If it matters, this is all plugged into a raspberrypi.

With a single compac plugged in to the hub, and the potentiometer at about 9-oclock (0.74v?), I've run at 350MHz for about 7 days. I haven't tried going any higher yet. I've got a fan blowing on it, and things seem ok. Haven't wanted to try and push it more just yet.

With two compacs plugged into the hub, and the potentiometer at about 9-oclock (0.74v?) for one and 0.77v for the other, I can't run any higher than 250MHz, or else one of the compacs starts hashing, but after a few seconds goes zombie. Then it starts again, and shortly after goes zombie. I've tried 300 and 275, but no luck.

I'm assuming my issue is power to the compacs, and that the hub I have just can't keep up. What would be the best way to confirm this? I don't have any other hubs, and I don't know that I want to spend $35 on a superbrag (i've seen it mentioned here multiple times) right now until I can fully rule out my hub as the drag.