Apple iMac 21.5 inch has Intel Core i5-2400S (2.5 GHz quad-core)
Apple iMac 27 inch has CPU of Intel Core i5 2500S (2.7 GHz quad core).
In Apple iMac 21.5 inch we will be able to get GPU of AMD Radeon HD 6750M (512 MB) and AMD Radeon HD 6770M (512 MB) in Apple iMac 27 inch. You will be able to get RAM of 4GB DDR3-1333
