Hello, I am really interested upgrading graphic card for lovely 21.5" iMac graphic card. There is already known post regard upgrading same model as mine but with 680M http://forums.macrumors.com/showthread.php?t=1596614&highlight=graphic However, there are few downside with following post 1. Losing initial boot screen (due to incompatible VBIOS) 2. TDP and power consumption. 3. Pricy! (about $500+@ on ebay) So, I decided to approach in a different way by using Geforce 660M There are few reasons that I decided to use 660M 1. 2012 iMac is using 660M (512MB but still same chip) 2. Low TDP 3. Cheaper (about $250) Before I approach this major task, I am missing only one piece; iMac 660M VBIOS I was searching in the web for few days and I failed to achieve the VBIOS. So, if someone can please provide me the iMac 660M VBIOS, I will proceed upgrading and post results of upgrade Thanks.