Cheapest small computer that can drive a 4K display, quietly?

[AdySan]

I'm running Blue Iris UI3 in Chromium on a Raspberry Pi 3 and it's driving a small HD monitor and that seems to work great. However, I want to replace the display with a much larger 4K TV. What would be a good computer dedicated for this purpose? It doesn't really need to be beefy, just enough to drive a 4K display and stay quiet with Chrome running BI UI3. Most cheap laptops would probably make the fans go crazy.

I have an older (2005ish) mac mini, but those dont drive 4K displays, so need something modern. Any ideas?