T420 maxed out that I use for school. i7-2640m, 16gb ram, 500gb SSD. LOVING IT : r/thinkpad
16GB KIT (2 x 8GB) for IBM Lenovo ThinkPad T Series T420 T420i T420s T520 T520i. SO-DIMM DDR3 Non-ECC PC3-10600 1333MHz RAM Memory. Genuine A-Tech Brand. at Amazon.com
A-Tech 96GB (6x16GB) RAM for Dell PowerEdge T320, T420, T620 Tower Servers | DDR3 1600MHz ECC-RDIMM PC3-12800 2Rx4 1.5V 240-Pin ECC Registered DIMM Server Memory Upgrade Kit at Amazon.com
the t410s is a super device. I will upgrade the ram to 16gb. sometimes prefer the t410s over the t420 or t430 : r/thinkpad
Upgraded the twins today. T420 got 16gb ram and a sled battery. 9cell + sled = 17hrs battery life. T480 got an extra 16gb of ram, up to 32gb. Happy with the
CMS 16GB (2X8GB) DDR3 10600 1333MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with Lenovo® Thinkpad T420 4177, 4178, 4180, 4236 Series - A13 at Amazon.com
A-Tech 16GB RAM for Dell PowerEdge T320, T420, T620 Tower Servers | DDR3 1600MHz ECC-RDIMM PC3L-12800 2Rx4 1.35V 240-Pin ECC Registered DIMM Server Memory Upgrade Module at Amazon.com
CMS 8GB (1X8GB) DDR3 10600 1333MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with Lenovo® Thinkpad T420 4177, 4178, 4180, 4236 Series - A14 at Amazon.com