Has the BMW iX3 come closest to being a true zonal E/E architecture with the Neue Klasse?

SBD investigates the various aspects of BMW iX3 architecture that stand out

The term zonal architecture is one of the most overused phrases in the current SDV era. From disruptive brands like Tesla and established premium brands like Mercedes-Benz to regional giants like BYD, nearly every major automaker has zonal architectures in its 5-year/10-year roadmap, if not its immediate plan. 

However, from an implementation standpoint, none of the production models has a true zonal architecture. Most of these models are in a transition phase, wherein legacy domain controllers, multiple gateways and many distributed ECUs coexist with a few ‘zone-based’ controllers. In a nutshell, these OEMs have defined zones (often as left-right-front-centre) but haven’t really realized the original promise of a true zonal E/E architecture.

Let's see an example: Xpeng G9 has one of the most advanced E/E architectures in the industry with multiple domain controllers hosted on a Gigabit Ethernet backbone. The OTA updates are spread across multiple domains supported by a robust AI-centric software stack (XNGP). 

G9 features some ‘zonal’ elements, but its architecture is still fundamentally designed around functional domains, not physical zones. 

G9 has powerful centralized and domain-centric HPCs, however, they are still assigned to specific tasks (e.g., ADAS via NVIDIA Orin, cockpit via Qualcomm Snapdragon). These functions continue to reside in domain-specific controllers scattered throughout the vehicle (as opposed to specific zones)

In a nutshell, the G9’s architecture still asks, “Which function should this domain process?” rather than “Which zone is this located in?”. 

This is consistent in various other Chinese brands as well (Xiaomi, Denza, Nio).

BMW flips this philosophy with the Neue Klasse platform (on iX3). 

Neue Klasse is the first clean-slate SDV attempt from a traditional automaker

BMW iX3 is the closest production vehicle (as of 2026) in which centralized computing, lightweight zonal controllers, Gigabit Ethernet, low-speed IP (Ethernet 10Base-T1s), and software-defined power distribution are integrated right from the beginning rather than layered onto legacy domain architectures.

Neue Klasse isn’t just an incremental upgrade in terms of compute performance, it’s a complete overhaul with a much-simplified E/E design, something BMW aspires to roll out in a wider lineup. 

ECUs lose their significance largely in BMW Neue Klasse

While G9 aims better ADAS, diversity in OTA, more computing power and AI capability, BMW Neue Klasse is a more profound architectural shift with reduced wiring, reduced ECUs, zonal power management and much more. 

One of the most noteworthy aspects of iX3 is the 600 meters of wiring reduction with a 30% reduction in harness weight. In the Neue Klasse architecture, the sensors and actuators connect to the nearest zonal controller, rather than having long dedicated wiring runs to distant ECUs. The vehicle needs only high-speed Ethernet between zones instead of multiple long copper wires across all domains. 

Additionally, because the compute intelligence is centralized in the four ‘Superbrains’, everything else has become increasingly ‘thin’. This means everything outside these Superbrains becomes merely an I/O device (an interface to the physical world) and very little application logic lives there. 

A ‘thin’ edge node is cheaper, reusable, and easily replaceable, reducing overall software duplication. BMW doesn’t have to deal with multiple software stacks powering various ‘fat’ ECUs, it simply needs one unified stack with I/O controllers.

For e.g., in traditional architectures, every ECU gets its own processor, memory, application software, CAN communication stack, etc. 

Take, for instance, the body control ECU in a traditional domain-centric E/E design. This ECU runs everything locally: window control, mirror control, seat control, door locking, diagnostics, etc. In the BMW iX3, all the heavy processing happens in the Superbrain, and the edge node no longer performs complex computation. It is simply reporting small events like, ‘window switch press’, ‘door opened/closed’, ‘ambient light status’ that are deterministic and low-speed. 

The emergence of Ethernet 10Base-T1s: Low-speed IP

One of the major complexity challenges faced by traditional automakers is the co-existence of multiple networking protocols: CAN, LIN, Ethernet, FlexRay, MOST. Each protocol has its own software stack, gateways, diagnostics and cybersecurity. 

The BMW iX3 largely reduces protocol diversity.  By using Ethernet 10Base-T1s, BMW extends Ethernet to many low-bandwidth edge devices such as switches, sensors, lighting modules, and comfort electronics. It is important to note that the aim is not to ‘replace CAN with Ethernet because it is better’; the aim is ‘fewer discrete networks'. 

Ethernet 10Base-T1s costs less than high-speed Ethernet, is IP-enabled and deterministic and can be shared by multiple devices (multi-drop topology). 

Do all these offer BMW a long-term advantage?

The software is centralized, so introducing a new feature no longer requires a massive overhaul or the redesign/repurposing of domain controllers. It only needs a modification in the software running atop Superbrains. 

Further, zonal controllers remain largely unchanged because they simply provide local connectivity.

This means the same Superbrain-oriented architecture can be replicated on a wider range of models (from compact crossovers to luxury sedans with varying software configuration rather than a fully E/E redesign. 

New ADAS, AI-powered cockpit features, battery optimization and other user experiences can be delivered via software updates while retaining the same zonal design. 

Finally, since the ECU has lost its ‘computing’ significance, the software is no longer tied to specific ECUs which means BMW can source hardware from different suppliers independently of the software. 

"Most traditional brands are in the ‘renovation’ phase. They are introducing certain zonal concepts on top of the legacy E/E. The Chinese brands are one step ahead and already have defined zones, but the E/E is still pretty much centralized and domain-centric. BMW has completely redesigned the vehicle around centralized intelligence and geographically distributed I/O nodes, bringing it one more step closer (if not completely), to what the industry has always envisioned as a true zonal computing architecture"

Shamik Ghosh - Product Owner at SBD Automotive