Hello, Does anyone know if this would work in my iMac? http://www.ebay.com/itm/1-HYNIX-4-G.../121468179893?ssPageName=ADME:X:BOCOR:US:1123 I think the speed might be different than what comes stock with my comp. Currently there are two sticks of 2gb at 1333. I plan on adding this in my third slot making the ram total 8. Just wondering if there would be any issues with my comp if im running mismatched sticks.