Ok, I manage to get my PC connect to the iMac 27" and you need some specific hardware and cables to do that. As most of the people know, A PC with ATI HD 57xx and HD58xx connecting to iMac 27 or Apple Cinema display 24 doesn't work. However, HD 5970 or HD 4870 does work. The problem is, HD 5970 is too damn expensive while the 4870 is just too slow for a 2010 PC. Recently, I found out Nvidia video card also offer displayport, and this is how I get it to work. 1. Get a Palit GTX 465 or GTX 470 video card. The newer version of these video cards come with a displayport. (The newer one equip with 2 fans on the top while the older version only have 1 fan) http://www.guru3d.com/news/palit-nonreference-geforce-gtx-470-w-custom-cooling/ http://www.guru3d.com/news/palit-geforce-gtx-465-dual-fan--4-video-output-/ 2. Get a Mini displayport to displayport cable. I found 2 vendors on the Internet that sell these. http://cgi.ebay.com.hk/1-8M-Mini-di...le_Parts_Accessories&hash=item3a5c44d74b#shId http://www.monoprice.com/products/p...=10246&cs_id=1024606&p_id=6006&seq=1&format=2 Once you get all these, the rest are simple. Plug the cable in the displayport of the video card, and the other end plug into the iMac or Apple Cinema display. Now, you can enjoy your PC with 2560 x 1440 pixels! Lets imagine you will play Starcraft2 on these.... Note: Credit to a guy in apple forum of hardforum.com to be the first lab rat on testing the Palit video card.