Tesla’s new self-driving (HW4) computer leaks: here’s a teardown

Tesla’s new self-driving computer, Hardware 4.0 (HW4), has leaked as the automaker appears to be already building some cars with the upgraded system.

Here’s a first teardown.

We have known that Tesla has been preparing an upgrade to its Autopilot/self-driving hardware for a bit now.

Most notably, Tesla filed with the FCC to add a new radar on its vehicles and said that it planned to start marketing it in January.

A new radar would mean that Tesla plans to update its sensor suite for Autopilot and self-driving.

We have also heard that the automaker is changing its cameras, according to a filing with Chinese regulators.

Finally, Tesla is expected to produce a new self-driving computer to merge all those new sensors into a more powerful computing platform.

All these hardware changes have been stressful for Tesla owners since the automaker has been promising that all its vehicles built since 2016 have all the hardware necessary to achieve self-driving through software updates.

It turned out not to be true as Tesla needed a more powerful computer (HW3), but it did supply the retrofit to existing owners for free.

Now CEO Elon Musk confirmed that Tesla will not provide retrofit to HW4, but he said that the automaker still plans to deliver on its self-driving promises with HW3 and that HW4 will only push the performance higher.

Tesla Autopilot/Self-Driving Hardware 4.0

The teardown comes courtesy of Green The Only, a well-known Tesla hacker and tinkerer who has consistently revealed a lot of new information about Tesla vehicles by hacking the automaker’s software and tearing down its hardware.

In this case, he managed to get his hands on a new HW4 computer from a new Model X vehicle. We won’t go into details about how.

There are some indications that Tesla is implementing the new hardware suite in the Model X first with the automaker having just put up for sale its display and test drive fleet, which Tesla generally does later in a quarter. It could mean that Tesla is liquidating its Model X units in preparation for the new hardware.

Green started the teardown by confirming what Musk recently said: don’t expect a retrofit.

Tesla’s self-driving computer is combined with its infotainment computer, which has also been updated with this HW4 upgrade.

Green said about the change:

Infotainment was reworked compared to current units. The GPU is now on the same board, so no more GPU daughterboard. This makes the whole unit thinner, otherwise no changes there – same 256G NVMe and 16G RAM, same AMD CPU and GPU.

As for Tesla’s actual HW4 computer, Green sees less improvement than what was hoped:

He did note that there are some improvements in security. Musk mentioned hackability of self-driving vehicles was a top concern at Tesla.

On the downside, the hacker’s own measurement shows that the new board has a higher power consumption than HW3 when idle.

Green noted that Tesla has also made improvements to the redundancy of the system, which is obviously important in a self-driving vehicle:

Redundancy is the name of the game this time? The board is mostly symmetric, with identical power connections on each side. There are even two network links to infotainment. Yet… if you unpower the A side, that kills the network switch and the link is lost. Still the improvements are there.

Now for what people have all been waiting for: the sensors.

Obviously, this is the computer and not the sensors, but the connectors can give us more information about the new sensors in HW4.

Now Tesla has been moving to a vision-based (cameras) approach and it has made a big deal of removing its radar and ultrasonic sensors.

There’s good news with HW4. Tesla appears to be including more cameras. There are currently 8 cameras in Tesla’s hardware suite, but now the new computer has connectors for 12 cameras – although one connector is marked as “spare”.

So we are talking about likely 11 cameras. Now as for the camera placement, it looks like all the current cameras remain other than a two camera setup in the windshield rather than the current three-front-facing camera setup.

While the information is hard to decrypt, Green sees indications that Tesla might have added cameras in the bumpers:

What’s SVC you might wonder? According to Tesla EPC, SVC is a bumper cover. So I’d guess these are bumper cameras. There’s a huge blindspot upfront on legacy cars up front (welcome to the legacy camp, Plaid owners!), so front bumper camera and two in the (rear?) bumper corners for cross traffic alerts (esp. with pillar moved forward)?

Green also found a connection for a new GPS module with a triband antenna:

The hacker noted about the new GPS unit:

The unit itself is big and unmarked, so who makes it is unknown, I would not be surprised if it’s somewhat custom Tesla thing. They carry a bootloader for it in firmware.

Finally, Green also found evidence of Tesla’s integrating a radar back into its sensor suite:

Musk told Electrek in June of last year after Tesla stopped using its radar:

The probability of safety will be higher with pure vision than vision+radar, not lower. Vision has become so good that radar actually reduces signal/noise.

However, the CEO also added that Tesla might still use radar if it had a “very high-resolution radar”:

A very high resolution radar would be better than pure vision, but such a radar does not exist. I mean vision with high res radar would be better than pure vision.

We saw some indications of Tesla working on that. We previously reported on Tesla looking to add a new “4D” imaging radar with twice the range of its previous radar.

That high-resolution radar was codenamed “phoenix” so it might be the very radar that makes it to the new hardware suite.

It’s not clear when Tesla plans to make the new HW4 official, but the timing of the March 1st Investor Day makes it a likely contender for an official announcement.