Hello !

Theoretical that should be possible. The OptiPlex 3000 SFF has an DP 1.4 and that should be enough for 4 separate displays, but you need special displays.

Here is an helpful link from the dell website How to Daisy Chain Multiple Monitors Using DisplayPort Multi-Stream Transport (MST) | Dell Deutschland.

But I am not really sure that the internal graphics card is strong enough to control 4 displays.

Best regards Frank