Newbie here.. I have a new computer that only has 2 drive bays. One drive is for the OS and the other is a 1TB I use right now for my lightroom pictures (500GB). I have about 13 years of home videos (3TB) that are split up on 3 1TB drives right now. I understand I should use two drives for video editing, one for writing and one for data. So, would a 4TB external USB 3 enclosure be best for my needs and use the 1TB internal drive as my scratch drive? I was thinking I should make the external drives into a RAID 1 for speed.. Maybe I could move the pictures to it also. As for back up, I was going to get 1 4TB external WD Book drive. Any advice would be helpful.