I believe that this is the correct line-up of the CPU models for each of the iMacs in the 2011 refresh. It may be useful with all of the questions floating around. Please let me know if I've got anything wrong. iMac 2011 Benchmarks The figures are time taken in seconds. Lower is better. iMac 2010 Benchmarks for comparison Please note that I was not able to find comparative benchmarks for the exact same processors in all instances so I used similar chips and have indicated as such. It will still give an "indication" of performance for simple comparisons. Benchmarks are from www.tomshardware.com Benchmark Explanations Audio Encoding: iTunes 18.104.22.168 (wav to aac Audio) - encoding Terminator II soundtrack from wav to AAC Image Processing: Adobe Photoshop CS 5: Applying 6 filters to a 69 MB TIF image Handbrake transcode time (mpeg 2 to H.264) : Big Buck Bunny (720x480, 23.972 frames) 5 min., Audio: Dolby Digital, 48000 Hz, 6-Channel, English to Video: AVC1 Audio1: AC3 Audio2: AAC (High Profile) Image Rendering: 3DS Max 2010: Render space flyby 1440 x 1080 Charts Note: These comparisons are based on pure cpu power and do not account for any other differences in the model line-up. They also do not account for any CPU throttling that Apple may, or may not, have applied.