Use um- "Komputerbay" as a memory for my iMac 27 "Sounds? At first not only something strange and yet not really opportune for an expensive iMac. But the reality is different! Both 4GB DDR3 RAM bars were quite hastily additionally built into the Mac and for the first time the system is started it. Oh, damn, a mistake! Memory again properly pushed into the appropriate slots and snap. And then- wow! Immediately display the apple of iMacs. Result: Various programs - especially in terms of graphics processing - run clean and absolutely off promptly. That's how it should be! The time, however, give a clear answer about the true quality of memory. I am satisfied and have way to save a few Euros.