Zack, known as @BLKMDL3 on X, recently shared his experience with Tesla’s Full Self-Driving (FSD) software version 12.5.1.5 in his 2019 Model 3 equipped with Hardware 3 (HW3). The drive yielded generally positive feedback, with both notable improvements and minor regressions observed.
This was part of Tesla’s rollout of FSD 12.5.1.5 on late Thursday evening to a handful of owners, with software update 2024.26.20.
Improvements were particularly evident in the vehicle’s response times to traffic lights. Zack reported that the FSD no longer hesitates at green lights, responding immediately, which he described as “immediately noticeable and welcomed.” The behavior over speed bumps also saw enhancement, with the vehicle now slowing down appropriately rather than driving over them too quickly, a significant improvement over the previous version 12.4.3.
However, Zack noted several regressions during his drive. He experienced some jerky steering wheel movements during unprotected left turns (UPLs), though he did not find it overly problematic. Additionally, the vehicle consistently drove 10% below the speed limit, even in assertive mode, prompting Zack to manually press the accelerator on a few occasions due to the slow pace. This issue persisted even after turning off the AutoMax feature.
Zack highlighted a positive moment when the vehicle detected and slowed down for pedestrians crossing a dark street at a considerable distance. However, he remarked that, compared to HW4/AI4, the system appeared less confident and slightly less smooth, noting that he plans to conduct further tests in daylight conditions before making a final assessment.
He expressed gratitude to the Tesla AI team for their efforts in releasing this update for HW3/AI3 owners and voiced hope for continued support for HW3 in future updates. He plans to continue testing the system under different driving conditions to gather more insights.
How did Tesla achieve FSD 12.5 on HW3? Ashok Elluswamy, who heads the Autopilot and AI teams at Tesla, provided insights into the challenges and advancements in the FSD software on Wednesday.
“We were able to achieve similar performance as the AI4 12.5 release with a relatively smaller model for AI3. Deploying the larger model requires us to implement a few kernels in the compiler to emulate the same operations that are natively supported on the AI4 hardware. The team is actively working on implementing and verifying those operations,” he explained.
“Combined with other model compression techniques, we think we can run the same 12.5 model on both the hardware platforms in the future. That said, model parameter count is just one of the many axes of performance improvement. Dataset distribution, dataset quality, model architecture, training compute, etc., also have tremendous impact on the final performance,” Elluswamy stated.
Elluswamy also touched on the anticipated launch of Tesla’s Cybertruck, saying, “Cybertruck will start with parking assistance features, given that it ain’t exactly the easiest vehicle to park. Initial release is slated for the end of this week. FSD for Cybertruck expected in September.”
This is great news for Tesla owners with HW3 vehicles to finally get FSD 12.5 as promised. Elon Musk said it was coming in “10 days” at the end of July, but we are glad the team is taking its time to release it and get it right. We can likely expect a wider rollout of FSD 12.5.1.5 to more HW3 vehicles over the coming days and weeks. Stay tuned!
