My iMac is the old 21.5inch 2009 version with a max display resolution of 1920x1080. May I ask if I can connect it to a Dell U2713H/U2713HM monitor and use its max resolution of 2560x1440? If I can, which of the following 2 ways to use to connect the iMac and Dell monitor? 1. use "Apple's mini displayport to dual-link DVI adapter" and "Dell's dual-link DVI cable"? or 2. use a "mini displayport" to "displayport" cable? Thanks!