I have a brand new Asus K501U laptop. It comes with a measly 16GB m.2 SSD (D:). I am glad for that because it means not paying an expensive premium for more.
Windows 10 was on 2.5" 1TB hard drive (D:), and it was almost unusable (after having been using a SSD for Windows for more than a year) with the non-stop disk thrashing. It was a 30-second wait for the Start menu to show after pressing the Windows key.
I bought myself a Samsung 850EVO 500GB SATA M.2 for less than US$200. It installed easily (I took the risk of leaving the battery online because I couldn't figure out how to remove that battery connector) and it was totally compatible. Asus kept reminding me that installing my own M.2 SSD voided the warranty. However, there were no stickers or seals so I could put back the original 16GB one if I ever need to seek servicing.
My goal was to use the M.2 SSD for Windows (C:) and then to move the 2.5" 1TB SSD over for my data.
The darn thing was that I could not boot Windows 10 off a thumb drive to install the OS onto the M.2 SSD and making it the C: drive. I wasted a lot of time finding out how because only one of the following EIGHT permutations work:
- Secure Boot: Enabled or Disabled
- SATA mode: ACHI or RAID
- Launch CSM: Enabled or Disabled
- Secure Boot: Disabled
- SATA mode: ACHI
- Launch CSM: Enabled
I had to physically remove the 2.5" hard drive first. Maybe it's because the hard drive had claimed the C: label.