Uh, it's complicated... The Intel iGPU has a limit of three monitors. DisplayLink is a whole other animal. Anything connected via USB is 99.9% DisplayLink, there are a couple other similar solutions to DisplayLink but they are almost unheard of. I believe there is also a total bandwidth limitation (sum of all resolutions). As seen here anyone who has exceeded 3 is using a USB connection in the mix. I've heard of people using six monitors via USB but those monitors were low resolution. Also USB/DisplayLink is usually not (never) suitable for high interactivity like games but will suffice for office work etc.