Hi all, I purchased a 27" imac i5 2.8ghz this week but still kept my 21.5" until i'm happy with the 27" and decided its right for me. I got the 27" and started to get headaches so didn't put the 21" onto ebay until really happy with the 27" Anyway, I have the 21 and 27 on the same desk and decided to run some tests. When loading apps the 21" is faster. The 21" is a 3.06GHZ core 2 with 4GB ram and a ATI 4670 video card. The 27" is a 2.8ghz quad i5 with 4GB ram and ATI 5750. Most apps loaded a few seconds quicker on the 21" Mail, firefox, calander, settings etc etc Then I loaded SC2 and again the 21" loaded quicker. The 27" runs around 33FPS at native res and high settings. The 21" runs 45fps native res and medium. But I couldnt tell the difference in detail between the two machines, only the load times were quicker on the 21". As soon as I set the 21" to high settings it killed the fps. I've also noticed the 21" has a 1TB SATA HDD make Hitachi and the 27" has a 1TB SATA HD make WD. The 27" HD noise can be heard quite alot of the time but you can never hear the 21" Is this the model ? or because the 27" is larger and carrys the sound more ?