I'm currently using an early 2015 13 inch MacBook Pro with Intel Iris Graphics 6100. I'm trying to use 3 external monitors, but I can only get 2 to work. I've seen people suggest using an active cable, but all of their suggestions are for MacBooks with a dedicated graphics card.
Will an active cable be enough for my situation, or do I have to buy some other, more expensive piece of hardware?
Officially Apple only supports two external displays on this model.
More specifically, it supports an HDMI-compatible device, including 4K, while using one Thunderbolt display or it can support up to two Thunderbolt displays.
In terms of external resolution this model supports up to 3840 x 2160 pixels at 30Hz or 4096 x 2160 pixels at 24Hz via HDMI and up to 3840 x 2160 pixels at 60Hz via Thunderbolt.
You could investigate external graphics card options, but I would suggest living with the two displays instead. However here are some resources that may help you decide:
