do you have trouble with port flopping? Here is "answer" from support.This "trouble" is writen nowhere in specification. RB3011 is CRAP and Mikrotik makes bad device.
The reason for port flapping is that you have different kind of devices connected to the same switch group. When you have 1Gbps devices connected to the same switch group with 100Mbps devices, the switch buffer needs to be cleared before forwarding traffic to the next port, but when you have mixed speeds it can't keep up clearing out the buffers so it flops the port. This is a RB3011 switch chip specification, there isn't much you can do, you must use the same speed Ethernet devices to avoid this.