Before you go any further, may I ask why you wish to set up a RAID0 array? The only advantages are (I think) that you can treat both disks as a single entity, and that the write speed is a little faster. These are minor compared to the disadvantage that, if either disk develops a fault (twice the chance of that for a single disk), you will lose your operating system, your programs and your data if you do not have back-up copies of the lot.
A RAID1 system, on the other hand, although it appears to be a single disk, contains sufficient redundancy that the failure of a single disk does not lose any information, and the system can be re-built when the faulty disk is repaired or replaced. The main disadvantage of course is that the capacity of the array is only that of the smaller of the two component disks.
For an example of the results of adopting RAID0,
As I've never set up a RAID0 array, I can't help with your main problem except to say that establishing the array might be very slow - an hour or more - but I would have expected that there would be a progress message on the screen. It's done at an early stage in the booting process, so communications are primitive.