Answer to: Intel i3 replace to Intel Xeon X3470My iMac11,3 was upgraded to Xeon X3450 last month, everything works well except two places: 1. in system profile it sill show as i3, but other info is correct, e.g. 8MB cache; 2. Process monitor displays only one thread on the bar, but system use 8 threads; it is recognized and utilized correctly by BOINC under OS X and BootCamp Windows 8 So, conclusion is, for 27 iMac i3/i5 owners, go ahead replace it with 1156 Xeons. It is almost half priced of i7 -860/870. Hope this helps someone in confusion.