Recommended SSD's for Nitro AN515-55

Yes this is a common problem these days with the new laptops that only provide a 512GB M.2 boot drive, Acer mainly uses WD M.2 SSDs or Hynix types also, you probably have a 512GB type M.2 SSD PCIe 3 x4 (which btw I've got in my AN515-56 and I had a WD SN530 type boot drive) and I had the same problem, lack of space and the boot drive got full, and I've upgraded the PCIe 3x4 drive to a 1TB and speedier PCIe 3 x4 drive, don't upgrade to a PCIe4x4 as your laptop will never ever utilize the PCIe4 x4 speeds and you will waste your money, what I've done is I've upgraded to one of the top PCIe3 x4 M.2 SSD drives which is either the WD SN770 or the SN750 Black or you can go for the more expensive Samsung 970 EVO Pro or Plus NVMe M.2 SSDs.

The only reason that I bought a 1TB WD SN770 Black M.2 SSD drive was because Acer had a WD oem M.2 drive and this M.2 drive was much cheaper than the Samsung 970 Pro or Plus, then I cloned the new WD SN770 Black M.2 SSD drive from the 512GB WD SN530 M.2 SSD (btw, make sure that you clone the new M.2 drive internally and fit the new drive into M.2 slot #2 of your laptop) as its 100% quicker than using any external adaptor and the clone only takes about 5min, I used the official recommended WD cloning software the Acronis True Image, then and after everything was 100% and all was tested for a few days, I formatted the old 512GB M.2 SSD and I'm using the 512GB M.2 drive as a slave, as that is a very good way of utilizing the oem drive but you can discard the oem 512GB and just use it as an official backup of your OS, and use the new 1TB M.2 SSD or even a larger M.2 SSD boot drive and fit another 2TB M.2 or even a 4TB drive into slot #2 as a slave M.2 drive on top of a 2.5" SSD or mechanical HDD. Those are your options, good luck and hope this helps you out.