Best answer: Lenovo's 2nd Gen ThinkPad X1 Extreme can support up to 64GB of DDR4 SODIMM RAM and is user upgradeable if you're keen on doing the work yourself.

The ThinkPad T14 (Gen 2) comes with either 8GB or 16GB of RAM soldered to the board. There's an extra SODIMM slot available for upgrades; we run through the process in this guide.