I have an Xbox which is soft modded from a save exploit, i have loaded UnleashX onto my Xbox. I am wondering is there any limit to the size of hard drive i can use or the brand with no mod chip in the box or can i use any size?

Apple

750 GB is the max size without some sort of switch between two hard drives.

there is a compatibility list somewhere around the site.

here is the compatability list http://xboxdrives.x-pec.com/?p=list just make sure u read at list 2 or 3 tutorials before u add the harddive