To a 27' Imac retina w/16 gb of ram. I'm currently running a 21' iMac Icore I3 w/ 8gb of ram. My problem is with my current set up is how slow it gets when running multiple apps. I do a fair amount of day trading and have many apps running(fidelity,bloomberg,cnbc,moringstar etc) in addition to streaming radio. My question is will i notice a big improvement by this purchase or can i achieve the same improvement(screen size/retina aside) with adding additional memory to my current set up? Ant suggestions would be greatly appreciated.