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I see these Dual Link cables online but confusing as they have like a Y cable with two DVI ends and one HDMI end. My 7750 only has 1 DVI port so...
That is not a dual link DVI cable. Go to Wikipedia, it explains the difference. Long story short, dual link has more pins. I don't have any experience with an Amiga at this screenmode but have had similar problems with a PC - the higher resolution screenmode did not become available in display prefs until I switched to the correct cable. Even HDMI didn't work because with the particular monitor I was using (a 27" Dell display) it had a maximum input resolution of 1920x1080 through its HDMI port. A limitation of that particular model which was only resolved by using the correct cable. Good luck!
