Hello, Currently I run my 2011 iMac with 12GB of ram, where the configuration is 2x4GB in the lower slots and 2x2GB in the upper. I have a 4GB stick lying around that i salvaged from another computer that would fit in there, making it 2x4, and the one 2GB and one 4GB for a grand total of 14GB. The 2 and 4 wouldn't be matched pairs so I assume i would lose dual channel support in at least on of the slot pairs, or maybe both? Is my current configuration preferable to the one I'm thinking of? Theres no pressing need for it, I just thought that if it doesn't have any impact why not put that extra one in there. Thanks.