Low Resolution on Apple Cinema Display (A1083)

I have an Early 2011 MacBook Pro (running 10.13.3) and recently got a hand-me-down 30" Cinema Display (A1083). When I connected the DVI cable to my MBP via a Mini Displayport, the Display shows but the resolution is still 1280x800 and I can't go above that. I did updates and a PRAM reset and still can't figure out how to increase the resolution on the Cinema Display. Is there something I'm missing or is it not possible to get the Cinema Display to the 2050x1600 that it touts with my current setup. If I need to purchase an external video card, then I would gladly do so, I just want to make this work. Thanks for any advice.