loading game from usb H/Drive

[flower]

I have been playing a game from 2006 thats 6 years, i have it installed on my c drive but have installed it on a usb drive 400g in size (not the pen drives), now it runs on both drives but dose take just a small time longer to load from the portable drive.
I was wondering once loaded would there be any differance in speed.
Why do i ask, well the game is not a fast running game, more planning/table top game but on the portable drive when loaded has a better save optshion data base.
Is there any differance to running programs from usb drive against your main c drive.
Reg
any coments or tips on game running helpfull