I have an ASUS P6X58D-Deluxe board (socket 1366, triple channel memory, first gen i7) with 3 x 2 GB DDR3-1600 RAM installed, and I'm looking for a quick boost in performance that won't break the bank before I ultimately decide to do a brand new build sometime this summer or fall. I was wondering how sound it would be to buy a single 4GB stick to fill one more slot beyond the three that are being used now. I figure that as long as I'm not mixing speeds I should be fine, but the uncertainty comes in having one bank making use of triple channel and the other not. Would that cause any stability or performance issues?