whats the performance difference?

[daniel_bourton]

i am about to build a new machine what would be the preformance differnece bettween 2 of these http://www.overclockers.co.uk/showproduct.php?prodid=HD-081-SA&groupid=701&catid=14&subcat=940 in raid 0
or 1 1tb one?
is it worth getting 2 or not