Legit Reviews posted a review on the Diamond USB 3.0 to 4K DisplayPort Video Adapter
A quote from the article:
Are you looking for a simple and easy to use product that will allow you to hook up and utilize the real estate of a 4K Ultra High Definition (UHD) display on your aging PC? If you happen to be in this unfortunate situation you are in luck as the Diamond Multimedia BVU5500 USB 3.0 to 4K DisplayPort Graphics Adapter allows you to connect an older PC, laptop or even a tablet to a newer display and it supports resolutions up to 4K (3840 x 2160).Diamond USB 3.0 to 4K DisplayPort Video Adapter Review @ Legit Reviews