XPS 13-9380 Dual SSDs?

The 9380 does not have dual SSDs, in fact I believe the only SSD it does have is soldered directly onto the motherboard, though you can check its Owner’s Manual or Service Manual on support.dell.com to confirm. I don’t know of any 13” laptops from major vendors that support dual SSDs, in fact. Typically that only becomes an option on 14-15” systems, and even there it isn’t a given.

On another note, if your goal is to perform clones or backups, I’m not sure why you’re talking about RAID 0 in the same sentence. RAID 0 splits your data between multiple disks such that if any one of them fails, you lose the entire multi-disk array. So a RAID 0 consisting of two disks actually doubles your risk, because if either disk fails, the contents of the other will also be useless. RAID 1 is mirroring, which definitely makes sense as a data protection solution. 

There’s also actually quite a bit to be said for cloning or performing image backups to an external device though, especially given your priorities. Cloning or backing up internally is certainly convenient, but convenience often comes at the cost of security, as it does here. If you suffer a malware attack, it’s very likely that it would target both internal disks, for example, whereas if you had an external disk that was only connected during the brief times you actually wanted to update its contents, your backup would be more likely to be safe. An internal hardware failure could potentially knock out both SSDs while the external device would have been safe. Whatever you do, this should definitely not be your only backup mechanism. A clone is especially problematic because if your clone source disk suffers a failure in the middle of a clone job, you’re now left with an unusable source AND an unusable destination, so you’d have nothing. This is one major benefit to using image backups instead. Another is that you can keep multiple backups from multiple points in time. However, image backups have to be restored somewhere rather than being directly bootable, so if your source disk fails, you need to replace it before you can use your image backups, whereas a clone can be booted directly.

If you do decide to go the imaging or cloning route though, I would strongly look at Macrium Reflect, mainly because the paid versions include features called Rapid Delta Clone and Rapid Delta Restore. The former means that after the initial clone operation, subsequent clone jobs only have to replicate the changes since the previous clone job rather than replicating the entire source data to the destination every single time. The latter means that if you ever need to restore an image in order to roll back your system (as opposed to restoring to a completely new disk), the restore only needs to “undo” the changes that were made from the time of the backup until the current time rather than writing out the entire partition from the backup file. Ok large partitions, this capability can drop restore times from 1-2 hours to 1-2 minutes.

And if you want an external device that you MIGHT be able to boot from, look at the Samsung X5 SSD. Typical external devices use USB, which is a problem because Windows doesn’t allow itself to be booted from a USB device, but the X5 uses Thunderbolt 3. Not only is that much faster, but since a Thunderbolt device appears to the system as a PCIe storage device, I believe (though I have not tested!) that Windows will allow itself to be booted from there, though you will have to enable the BIOS options related to Thunderbolt boot support.