2 HDDs in RAID 0 + 3rd HDD



Hello guys.

I have a question about something I want to setup in my new system. I am willing to have a 320GB HDD for the OS and the programs, while having other 2 x 640 GB HDD in RAID 0 for my HD Video Working, Games and Huge Downloads.

What I want to know, How do 2 HDDs in RAID 0 show inside “My Computer” ? 2 HDDs with duplicate data but actually Half in First HDD and the other Half in the 2nd HDD or it will show as 1 HDD with both HDDs capacity assuming that the whole HDD capacity is one partition only

I assume that creating partitions is in the normal way or is there a different way to make partitions ?

Thank you :