Sony VAIO Y Series RAM: use 2Rx8 instead of 1Rx8 | Peter's Useful Crap
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
I've upgraded my iMac's memory/RAM but... | MacRumors Forums
4GB 1Rx8/2Rx8 PC3L/PC3 mix brand and speed SO-DIMM Memory RAM Lot of 11 | eBay