You didn't say what the native resolution is on your display.
Scaling to 4k can indeed use processing power. But laptops like the Mac Book Pros do it all the time.
A 4k monitor does not have a higher color gamut; in fact, I'm not sure there is any small 4k screen with a wider gamut. Color and resolution are independent of one another.
And whether your applications have user interface items that are too small depends on your system software and the applications. Macs that use retina screens, for example, use separate HiDPI graphics so that fonts and menus and such remain the same size.
Thanks for your reply!
The native resolution for the 4k display is:
15.6” 4K QFHD (3840x2160) Matte Display with G-SYNC Technology
Nvidia GeForce GTX 970M GPU with 6GB GDDR5 Video Memory
I'm leaning towards not getting the 4k screen if it will slow down my Lightroom editing. I believe if lightroom has to draw real time previews for a higher resolution, it will slow things down. If the color gamut is not wider, then I see little reason to get a 4k screen on such a small monitor.
The dell xps laptops are coming with screens that claim close to 100% Adobe RGB coverage, so I assumed other 4K screens had wide color gamuts. I really don't need to see crisp detail from a higher resolution on a work laptop. I'll invest in a nicer desktop monitor in the future, if I really need it.
Anything else I should consider with that 4K screen versus a Full HD IPS Matte Display with G-SYNC Technology (1920 x 1080) ?