whats better for my system ide or ahci?

[kevintaper]

as topic says, i have windows vista ultimate on raid 0 with 2 x 150gbs raptors, ive recently downloaded windows 7 and have it on a seagate 1tb hdd in ide mode, is there more perfromance with ahci enabled??, i.e can i change to it now from ide??, and whats is ahci mode, and the benifits? help would be appreciated

 

[kevintaper]

so thats the only diffrence?, all i have to do when i use the drive with windows 7 is change to ahci???????????