The Model X Long Range and Performance versions have the same 100 kWh traction battery, but are equipped with the new permanent magnet synchronous reluctance motors resulting in a better efficiency and longer range.
The Tesla Model X can be equipped with 5, 6 or 7 seats. The 5-seat configuration, which was introduced in November 2016, has the best-in-class cargo capacity (88 ft3). The 6-seat seat configuration (77 ft3) is the most expensive one. In July 2017 Tesla introduced a new 7-seat configuration where the second and third-row seats fold flat.
P90D, P100D and Performance.
To answer this question we have made a special timeline. Please, take a look.
September 2015
The Tesla Model X was initially offered with some Driver Assistance Features:
October 2016
Tesla releases new Autopilot 2.0 hardware suite for Model S and Model X. 8 cameras, 12 new ultrasonic sensors and radar provide 360 degree coverage around the vehicle with almost twice the sensor range and resolution of the prior version.
This new hardware will be utilized by two optional software enabling packages. Both can be purchased after delivery.
The first package is called Enhanced Autopilot. It is an improvement over the first Tesla Autopilot.
Full Self-Driving Capability — is a second optional software package. It is designed to be able to conduct short and long distance trips with no action required by the person in the driver’s seat.
Vehicles with 1.0 hardware will no longer receive autopilot updates.
August 2017
Tesla releases new powerful Autopilot 2.5 hardware suite for Model S, Model X and Model 3.
This is the minimum hardware version to get the built-in dashcam and a fully functional Sentry Mode.
Vehicles with 2.0 hardware will no longer receive autopilot updates.
To sum it up, all Model X vehicles can be equipped with Driver Assistance Features. But if you want Full Self-Driving Capability you should consider only vehicles with the Autopilot 2.5 hardware (produced after August 2017).