Tesla boss Elon Musk believes self-driving cars will take over the roads and human drivers could be banned from operating vehicles within 20 years.

If that sounds extreme, Musk likened the possible elimination of human-driven cars— "because they're too dangerous" —to other transportation systems like elevators which once had humans running them but don't anymore.

Musk sat down for a conversation on Tuesday with Nvidia CEO Jen-Hsun Huang on the first day of the GPU Technology Conference in San Jose, Calif., discussing Nvidia's role in the computing systems powering Tesla's Model S, how autonomous driving will be regulated and rolled out, and more.

The Tesla and SpaceX co-founder said driverless cars were inevitable and will be perfectly safe, but urged developers and regulators to take their time in greenlighting their expansion on our roadways.

"Doing self-driving is easier than people think," he said, but added that it wouldn't be a terrible thing to be "even more cautious with complicated systems like automated driving."

Musk said it was likely that cars would gradually add automated features over time rather than all at once. Vehicles could have systems that operate in a self-driving "shadow mode" even as humans drive them, producing data that will be enormously useful in readying future, fully-automated cars, he said.

The two CEOs also discussed Nvidia's contribution to the computing systems in Tesla's electric vehicles which run navigation, driver-assist functionality, entertainment, climate control, and more.

With Tesla set to push out an over-the-air software update for the Model S on Thursday which Musk earlier this week promised would "end range anxiety," Jen-Hsun asked if the current Model S computing platform was powerful enough.

It turns out that was a bit of a loaded question. Nvidia's Tegra-based platform used in the Model S infotainment system is a couple years old now, but the graphics chip maker is showing off some more advanced Tegra-based automotive solutions like Drive PX with Tesla, Audi, BMW, Toyota, and other car makers at GTC.