Do you need a DisplayPort cable for a triple monitor setup?

[HDMICable]

Hello, I have a Zotac GTX 660 that has a DVI-I (which I'll be using a DVI-I to HDMI Adapter with), a DVI, and an HDMI input. I was going to buy two more monitors, but one of my friends was like "No dude, you can't until you buy a DisplayPort or else the 3rd one won't turn on." Another friend was telling me that he was stupid and that you didn't need a DisplayPort. I looked for a good 20 minutes or so online and decided to just come here and ask. So who's right?

 

[chris987]

How To Setup NVIDIA Surround on GeForce 600 Series GPUs

Configuring Multiple Monitors - NVIDIA Surround (Single GPU)

 

[Mousemonkey]

With Nvidia cards you do not need to use display port.