Basically I want to connect my Win7 PC tower to my 27" iMac. After doing some research, is it true that only the ATI 4890 and ATI 5970 are the only video cards that have worked in the past? The newer 5870 Eyefinity 6 just got released and seems to be a bit cheaper than the 5970, seems to be untested still. Has anyone got this to work with the cheaper ATI cards with displayport? I don't want to spend more than $600 for this new venture. Any advice?