You WILL need a mains powered usb hub and the Y cable.
Search for this EBAY number :- 231892484263
It's got two male usb ends that both go into one female end (the end where the gekko goes). One side of the cable is data and power and the other is just power so you can be sure the gekko gets power from two ports not just one.
Thanks for that information, I got it now. But a good USB hub with external power supply would replace that cable anyway, right?
Maybe depends on the hub.
The majority of hubs are short on power and need a y cable to get the stick to run at 250 or higher.
You can get them pretty cheap to on ebay. I know I ordered a set I think from China and had to wait but it was very cheap per cable. With getting the Y cable you can get a lot more out of the compacs they are pretty amazing on OC'ing.