I have a Dell XPS 12 laptop (sometimes referenced as model 9Q33, bought in the UK), and information about the SSD's logical/physical interface and compatibility is very conflicted.
According to Device Manager, the card itself is a Liteon LMT 256 M6M mSATA 256GB).
But some web pages say the laptop is an 'older' model that takes an mSATA SSD rather than PCIe:
Unfortunately, no -- the older XPS 12 (9Q23 and 9Q33) used mSATA SSDs. The new models use PCIe/NVMe -- though the form factor is similar, the two are not interchangeable
and other web pages 'guarantee' it takes a PCIe SSD:
Samsung mini-SATA mSATA 512gb (gigabyte) Mini PCI-E SSD (solid state drive) for the following Dell Ultrabooks.
Guaranteed Compatible Dell Laptops / Notebooks:
-XPS 14 (L421X), 15 (L521X), 13 (L321X), 13 (L322X)
-XPS 12 (9Q23) / 9Q33
What kind of SSD is it, and how would I be able to figure it out in future?