[thrtythreeforty]

I've got a T480s that has 40GB of RAM (32GB SODIMM + 8GiB soldered). Works fine. Is the T480 different?

[drillsteps5]

T480 has 2 RAM slots and can support 64Gb (32+32). The reason it's "unofficial" is that when they designed it (and wrote PSREF) the 32Gb RAM wasn't a thing.

[kev009]

My T480 running NetBSD: [ 1.000000] total memory = 65411 MB

[nine_k]

T480 has 2 RAM slots and S has soldered RAM and 1 slot.

OTOH unofficially T480 (not S) can work with two 32 GB SODIMMs. I did not try that.

(I wish the AMD-based thinkpads supported ECC RAM. Ryzen 7 mobile CPUs technically allow for that.)