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
What does the 1Rx8 mean vs. 2Rx8 for RAM and are they compatible? (5 Solutions!!) - YouTube
memory - Lifebook RAM compatibility - Super User
Lot of 4pc Mixed 2GB 1Rx8 -2Rx8 PC2 - PC3; 1GB 2Rx16 PC2 - PC3 Laptop RAM Memory | eBay