Can you call it a limitation of the processor? I thought it was with the accompanying chipset - https://www.easytechjunkie.com/what-is-the-difference-betwee... .

Sure, the only real limitation inside the processor is the number of addressing bits if I remember correctly. However, in case of laptops I think it doesn't matter since they're kind of sold as a platform. The main point was - it might not be possible to extend RAM.

Thanks for the link. Indeed, that page lists a 16GB limit, so if that is the processor in OP's machine there may be hope. I do have 16GB (8GBx2) in my older X220 Tablet.

For the X250, I can confirm that it handles the 16GB. Investigated it once, haven't bothered actually upgrading, though.