RAID 1 is a mirror of the drive. It would give you only 1TB of space same as if you ran 1 drive. The advantage is if 1 drive fails you have an exact duplicate at all times. Honestly with an SSD this is a complete waste of time.
Performance wise you are likely looking for RAID 0 which will give you 2tb of space and in theory is faster. Except if 1 drive fails the whole array fails, and half your data is gone, you need to rebuild the whole PC etc.
That and its barely been found to make that much of a difference with SSD's. Its not worth it.
You don't even need to use a RAID controller for RAID 1, Windows 8.1 and Windows 10 Storage spaces will do this for you.
This is a good article describing how the different RAID levels...