How many monitors can W8.x support?

[Mr_Spock]

I'm looking to have up to 4 monitors in Windows 8.1. Two are 4k and two are HD.

How many monitors can Window 8.1 natively support? I think the maximum is 3, but its not obvious.

If I want 4 or more monitors in Windows 8.x what software do you recommend?

Does anyone know if Windows 10 supports more monitors?

 

[doubletake]

It depends on your graphics card. There are some older Eyefinity Edition AMD cards that have 6 mini-DP ports, I think that's about the most you can get out of one single card. Current Nvidia cards support 4 (one for every port).