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I heard (and wrote) about it yesterday. Zotac says it's compatible with any GPU so I can't see why it wouldn't work with iMac or other Mac. Keep in mind that you are limited to 1920x1080 per display though.
 
Thats great to hear, at the moment I have a Displaylink and the drivers just suck under lion.

Yeahh I can fully use 3 Screens with my 21,5" iMac without Lag :D
 
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