Lenovo ThinkPad T400 Hardware and Software Upgrade 2021 - YouTube
8GB Kit (4GBx2) Upgrade for a Lenovo ThinkPad T400 Series System (DDR3 PC3-12800, NON-ECC, ) Memory Cards - Newegg.com
memory - Does Lenovo T400 can only work with up to 4GB RAM? - Super User
8GB (4GBx2) Team High Performance Memory RAM Upgrade For Lenovo ThinkPad T400 Series T410 Series Laptop. The Memory Kit comes with Life Time Warranty. at Amazon.com