Tesla HW4: the new computer dedicated to semi-autonomous driving already dissected

Its name may not mean anything to you, but connoisseurs know that Green The Only is a famous hacker who loves taking apart Teslas, more specifically their on-board computer. Thus, he managed to get his hands on the HW4, the code name of the latest Tesla computer dedicated to the famous Autopilot, the semi-autonomous driving function (FSD).

As the site says Electrek, Tesla has been working on updating its Autopilot for some time. Thus, the American manufacturer would have informed the Federal Communications Commission (FCC) of the addition of a new radar on its electric vehicles. Another clue, in China this time, Tesla would have indicated to the regulatory authorities the change of cameras fitted to its vehicles.

The car manufacturer is developing a unique computer dedicated to semi-autonomous driving (FSD at Tesla) with a more powerful computer platform, where all the new sensors will be grouped. This is the HW4, successor to the HW3 which has been used to update the semi-autonomous driving of vehicles produced since 2016.

Green The Only took on the task of dissecting a HW4 salvaged from a brand new Model X. First confirmation of what Elon Musk said: it is not an update, except for infotainment.

Inside the box – whose format is changing – the graphics processor or GPU (AMD) is directly attached to the motherboard, thus favoring a thinner assembly. For the rest, no change: there are 256 GB NVMe SSD and 16 GB of RAM and identical CPU.

The HW4 itself doesn’t have any dramatic improvements except for a security boost against hijacking the autonomous driving feature. The system is still based on the Samsung Exynos, like the S22 smartphones, with 20 cores compared to 12 previously divided into five clusters of four cores, whose frequency varies from 1.37 (idle) to 2.35 GHz (full power ). The hacker also noted the transition from two to three cores of the TRIP Cores, whose maximum frequency peaks at 2.2 GHz.

With regard to semi-autonomous driving, the system is of course redundant with two SoCs per card in order to take over in the event of a breakdown.

According to Green The Only, this new material displays “much less improvement than many expected”. In addition, the new HW4 card consumes more power (80 W) at idle than that of the HW3 (100 W maximum at full power).

An increase in cameras

Another technical advance with the increase in the number of cameras, which would go from nine currently to 11 + 1 spare, knowing that their placement on the vehicle should not evolve, except at the level of the windshield. Indeed, the new configuration would plan to go from three to two cameras. Some rumors indicate that the removal of this third camera would be due to the change in resolution of the sensors, which would go from 1.2 to 5 megapixels. This resolution progression should be useful in “certain scenarios”.

According to Green The Only, three cameras should be integrated into the front bumper, without it being known in which direction they will point. A priori, according to the number of incidents reported, Tesla vehicles have a blind spot when they leave a secondary road visually obstructed by buildings or various objects. Hence the idea of ​​placing a camera in the front, capable of “looking” at the sides of the vehicle.

Tesla would also consider repositioning some of its cameras, in particular those of the B pillar, currently pointing forward. They could be moved on the wings to provide a better field of vision. Finally, said B-pillar cameras will have a heating system identical to that of the exterior mirrors to eliminate condensation.

An HD radar named Phoenix

The big change would be the return of the radar, removed since 2021 on the Model 3 and Y in favor of cameras. Looking a little closer at HW4, Green The Only found evidence of this radar being integrated, probably “very high precision” according to the hacker. We know that the manufacturer is working on the development of a 4D radar “with twice the range of its predecessor”, codenamed Phoenix. It remains to be seen whether this same radar will be integrated. What is sure is the presence of a heater avoiding an accumulation of snow and frost that can block the signals.

We could point out to Tesla that the French equipment manufacturer Plastic Omnium must soon market a bumper with 4D radar based on millimeter waves. Invention of the Greenerwave start-up, this 4D radar, whose “performances are close to those of LiDAR, but without the disadvantages”, alone replaces three radars placed at the front (one central and one on each side). Here, any body part of a vehicle can integrate a 4D radar.

It remains to be seen when the HW4 (also equipped with a new GPS module coupled to a triband antenna) will be deployed. March 1 will be Tesla Investor Day, during which Elon Musk could make an announcement about it.