7 monitoren for P3Dv4.5

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MY new PC: is i7-8700 3,2 GHz box 12MB Smart CAche processor - 2 videocards KFA2 nVidia GeForce 2070 8GB GDDR6
and 7 monitors ilyama prolite E2283HS-B3 21" .
In the middle starting P3Dv4.5 and i can stretched it out over 3 monitors. After that i stretched it out over the left and the right to all the 7 monitors. Then you see the horizon-lines and buildings has a corner it is not fluent. I watch many you-tube films about view-management and NVidia. But the problem is not solved.
Can somebody give me the advice to fill the 7 monitors with P3Dv4.5

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Extra information about my question, If I use 7 monitors the framerate gose from 55 to 2 framerates.