Beware of the single rank x16 RAM kits sneaked in some laptop models! The 1Rx16 modules have significantly lower bandwidth compared to the 1Rx8 variants - NotebookCheck.net News
want-to-change-the-ram-and-change-the-ssd-I-do-not-want-to-make-a-mistake-in-the-type - English Community - LENOVO COMMUNITY
Ramaxel – Page 3 – Tested Laptop Parts - Replacement Parts for Repairs
RAMAXEL 100280746 4GB 1Rx16 PC4-2666V-SC0-11 01AG829 SODIMM RAM for Lenovo 520 - £29.99 | PicClick UK