So you can either go with Displayport 1.2 monitors which have daisy chaining for 3 monitors to use 1 Displayport 1.2 port and the 4th monitor to use a 2nd displayport slot on its own.
For none daisychained monitors if you wanted 4 monitors via Displayport you would need to get a MST 1.2 displayport hubs like this one:
And a GPU with at least 2 Displayport 1.2 ports so that 3 of the monitors go into the hub and the 4th goes into the 2nd GPU displayport connector.
Alternately a RX 480 which has 3 DP 1.2 ports and get a 2 displayport MST 1.2 hub.
Using anything else could lead to syncing issues since running multiple monitors over a mixture of multiple outputs (DP + HDMI or DVI) means they would potentially refresh at different times.
Firepro cards can come with 4 displayports but they aren't really ment for gaming.
Obviously you would need Displayport 1.2 monitors for best results as again using HDMI or DVI adaptors can lead to sync issues.
thanks for your quick answer amdpete!!
So the framerate drop is related to not syncing with the displayports not being the same type displayport, like a combination Hdmi/Dvi,
Displayports has to be the same type.
I found this displayport hub, If I understand your advise this would definately solve my 4 monitor setup problem.
It isn't a framerate drop but it would look like tearing as the monitors would be using different timing due to having different interfaces if they were all not using the same inputs.
I haven't tried a 4 monitor DP hub, but I guess it would work.
Ok, I will order the 4 monitor DP hub then, I realy am struggling for many hours of trouble shooting.
Hopefully this wil solve my problem.
Thanks again for helping me out here amdpete!!