Most fast method to transfer game DVD or ISO into hard disk PS2

Hello, i ask how is the most fast method to transfer ps2 game disc or iso into hard drive ps2.I have tryed by lan but i have average speed about 1,2 Mb/s and by WinHIIP_V1.7.6 and i have average speed 2,1 MB/s .
It' s correct or have a more fast method.Thanks