Added a couple more cores and 12 more gigs of ram to my T520 : r/thinkpad
Lenovo ThinkPad T520 core i7 2nd gen 8GB RAM 256GB SSD Hard Drive Windows 10 Pro 15.6” Laptop with charger in Excellent Working condition!!! Specific for Sale in Aurora, IL - OfferUp
For Lenovo Thinkpad T520 W700 W710 W510 T510 T430 8x Dl Dvd Rw Ram Double Layer Burner 24x Cd Recorder Optical Drive New - Dvd, Vcd Players - AliExpress
Lenovo ThinkPad T520 core i7 2nd gen 8GB RAM 256GB SSD Hard Drive Windows 10 Pro 15.6” Laptop with charger in Excellent Working condition!!! Specific for Sale in Aurora, IL - OfferUp
OFFTEK 4GB Replacement Memory RAM Upgrade for IBM-Lenovo ThinkPad T520 (DDR3-12800) Laptop Memory at Amazon.com
Lenovo Thinkpad T520 i5-2520M 4GB RAM 300GB HDD 10 Pro NO POWER CORD | eBay
CMS 16GB (2X8GB) DDR3 10600 1333MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with Lenovo® Thinkpad T520 4239; 4240, 4241, 4242, 4243 - A13 at Amazon.com