I wouldn't put a lot of stock into information from 2008 in this case. There have been major memory controller changes in that period of time. Also, for those of you offering up advice, read up on what Intel has in the past called "flex mode" or "flex memory mode" or "Flex Memory Technology".
Ideally on anything other than an X58 board, 2 or 4 modules will give the best overall memory bandwidth. However, in a case like this one, if you "NEED" more than 8GB of memory, you'll do better with 12GB aka 3 modules.