Does anyone know if you can mix single and dual rank memory within a single computer? Here's the deal... I have some computers that have 6 DIMM slots. The computers themselves are limited to 8 ranks TOTAL. Currently all 6 slots are populated with 2GB, single rank DIMMs. What I want to know is, if I pull out 2 of the DIMMs and replace them with 4GB dual rank memory, it would up the total amount to 8 ranks (the max ranks you can have on them). And would upgrade the computers from 12GB to 16GB. Single rank memory is about 6x more expensive than dual rank... otherwise I would just go to 24GB by putting single rank 4GB DIMMs in all the slots. A 4GB single rank DIMM is $1,100, while a dual rank DIMM is $185.