Apple iMac MC813LL/A 27-Inch Desktop (OLD VERSION) 2.7GHz quad-core Intel Core i5 with 6MB on-chip shared L3 cache 4GB 1333MHz DDR3 SDRAM 1 TB Hard Drive, DVD SuperDrive 27" LED-backlit display , AMD Radeon HD 6770M graphics processor with 512MB of GDDR5 memory Mac OS X v10.7 Lion