Tesla CEO Elon Musk says the company will “most likely” start retrofitting its new, more powerful processing chip into older vehicles near the end of the year. The new FSD chip is the first to have been designed in-house. Tesla says it offers 21 times the performance of the Nvidia chips it replaces — a claim Nvidia disputes. The new chip has been shipping in Model S, X, and 3 cars since before its announcement, but soon it will be offered as an upgrade to half a million Tesla owners.

Elon Musk has made big promises about the new chip, which he claims has enough power to eventually allow for fully self-driving cars, if and when the software catches up. The upgraded FSD computer includes two of these new chips for redundancy. Despite being a lot more powerful, the company says the new chip costs 20 percent less than its previous “HW2+” Nvidia hardware, and only draws a bit more power.

The FSD chip upgrade will be offered for free to any Tesla owners who have paid for the company’s “Full Self-Driving” add-on package, which costs $6,000. In total, Musk estimates that there are around 500,000 cars that are compatible with the new chip, although not all of them will have paid for the package that will allow them to get the upgrade for free. The Full Self-Driving option currently gives you access to Tesla’s Navigate on Autopilot feature, which is capable of guiding you from “on-ramp to off-ramp” on highways, meaning it can suggest lane-changes, navigate highway interchanges, and can proactively take exits. Without it, cars are limited to regular Autopilot, which offers automatic steering on highways and adaptive cruise control.

The name of the Full Self-Driving package has been controversial. In October last year, the company stopped promoting the option, claiming that it was causing “too much confusion” for its customers. That’s understandable, since the Navigate on Autopilot feature it enables is a far cry from the “full self-driving” functionality implied. In spite of the criticism however, the option soon returned in February.

Correction: Article updated to clarify that not all of the 500,000 HW2 Tesla owners will get the upgrade for free, only the ones who have paid for the Full Self-Driving package.