X1 Extreme Expansion Opportunities - No Soldered RAM in this X1 - Every single X1 Extreme will accept 4TB NVMe + 64GB DDR4 RAM whenever you are ready regardless of what it
What does it mean if a laptop has soldered RAM? It also has a regular memory slot. - Quora
How to upgrade RAM in the ASUS VivoBook 15 | Windows Central
Teardown of Retina MacBook Pro finds soldered RAM, proprietary SSD | AppleInsider