Yes. You need to create a custom resolution with a specified refresh rate.
I've tried it and didn't notice any difference in smoothness on various dell IPS panels so I reverted back to 60 - it's a very YMMV thing though! I can get 85hz on both the 2713hm and u3011.
Thanks - found it in the control panel. Figured they would have a more polished tool considering how they were touting this feature. Haven't had a ton of time to test, but it definitely seems YMMV.