Tesla's FSD Hardware 4.5: A 3-Chip Upgrade Before AI5?
January 23, 2026
By Karan Singh
The Big Reveal: Tesla's FSD Hardware 4.5
New insights from the Tesla Electronic Parts Catalog reveal that Tesla is likely preparing to release, or has already begun using, a new HW 4.5 FSD computer in new cars. This upgrade could be a significant step up in computing power, marking a potential shift from minor revisions to a more substantial enhancement.
The Findings
The new component, explicitly listed in the official Tesla Electronic Parts Catalog, has been spotted by an eagle-eyed observer, Todd deRego. The part is named 'CAR COMPUTER - LEFT HAND DRIVE - PROVISIONED - HARDWARE 4.5' with the part number 2261336-S2-A and a price tag of $2,300.00, similar to other FSD computers on the EPC.
The 3-SoC Theory
Longtime Tesla firmware hacker Green offers an intriguing insight. While he hasn't physically inspected the new units, he notes that Tesla's firmware has long referenced a 3-SoC (System-on-Chip) design. Historically, Tesla's FSD computers (HW3 and HW4) have used a dual-SoC design, providing redundancy. If HW4.5 is indeed a 3-SoC architecture, it opens up new possibilities.
Why 3?
The third node in a 3-SoC setup could offer several benefits. Firstly, it enhances raw throughput, enabling larger and more complex inference models. As FSD models grow exponentially in size, a 3-SoC setup allows Tesla to split the inference load across more silicon, running larger, more intelligent neural networks.
Secondly, it introduces Triple Modular Redundancy (TMR). In a 2-chip system, disagreements can lead to safe disengagement and red-hands takeover warnings. With a 3-chip system, Tesla can implement TMR, allowing the system to 'vote' to ignore errors and continue driving smoothly, adding an extra layer of safety.
A Bridge to AI5
With AI5, Tesla's next-generation FSD chip, set for production later in 2026 and volume production in 2027, there's a gap in computing power. Software often outpaces hardware, and HW4.5 could be a stopgap until AI5 is ready.
Tesla's Robotaxi Revolution
In a historic milestone, Tesla has launched unsupervised Robotaxi rides in Austin, Texas, marking a significant step towards true driverless public transit. The company has removed the safety monitor from these vehicles, but is still monitoring them visually from a distance.
AI5: The Next Big Thing
Elon Musk confirms that AI5 will be a very capable chip, comparable to NVIDIA's $30K server chip in performance. Made in Texas, AI5 will power the cars and likely be the last major vehicle chip, with Tesla's Dojo 3 (AI6) focusing on server and inference training.
The Future of Tesla
With AI5, Tesla aims to advance FSD and solve existential challenges, ensuring its future success in the autonomous vehicle market.
