On IOS58 it says USB 2.0
Also the cIOS I install through d2x:
IOS249[57] (rev 65535, Info: d2x-v10beta52): Trucha Bug, Nand Access
IOS250[56] (rev 65535, Info: d2x-v10beta52): Trucha Bug, Nand Access
IOS251[38] (rev 65535, Info: d2x-v10beta52): Trucha Bug, ES Identify, Nand Access
Though on...