Deep dive into the Maia 200 architecture

Maia 200 is a breakthrough inference architecture engineered to dramatically shift the economics of large-scale token generation. As Microsoft’s first silicon and system platform optimized specifically for AI inference, Maia 200 is built for modern reasoning and large language models, delivering the most efficient performance per dollar of any inference system deployed in Azure and represents the highest performance chip of any custom cloud accelerator today. 

AI inference is increasingly defined by an efficient frontier, a curve that measures how much real-world capability and accuracy can be delivered at a given level of cost, latency, and energy. Different applications sit at different points on that frontier: interactive copilots prioritize low-latency responsiveness, batch-scale summarization and search emphasize throughput at a given cost, and advanced reasoning workloads demand sustained performance under long-context and multi-step execution. As enterprises deploy AI across these diverse scenarios, the infrastructure requirements are no longer one-size-fits-all; they require a portfolio approach that delivers the highest-performance, lowest-cost infrastructure at scale. 

Maia 200 reflects a core principle of AI at scale: innovation across software, silicon, systems, and datacenters is what enables us to deliver 30% better performance per dollar than the latest generation hardware in our fleet today. As agentic applications expand in capability and adoption, this integrated approach makes infrastructure efficiency a foundational advantage.  

Maia 200 Purpose‑Built for Price-Performance Inference Leadership 

To meet these demands, Maia 200 introduces a new system and silicon architecture purpose built to maximize inference efficiency. Guided by a deep understanding of AI workloads and supported by an advanced pre-silicon environment and enabling hardware/software codesign, Maia 200 incorporates a set of deliberate architectural choices that deliver industry leading tokens per dollar and per watt. Notable architecture innovations include:

Maia 200 peak specifications

• Optimized narrow precision datapaths, on the latest TSMC N3 process technology enabling 10.1 PetaOPS FP4, positioning Maia 200 among the highest FP4perdollar accelerator available in any cloud.  
• A reimagined memory subsystem combining 272 MB of ondie SRAM with 216 GB HBM3e delivering 7 TB/s of HBM bandwidth capacity to service dataintensive operations while minimizing off-chip traffic, reducing HBM bandwidth demand and improving overall energy efficiency. 
• An efficient datamovement fabric, centered around a multilevel Direct Memory Access (DMA) subsystem and a hierarchical NetworkonChip (NoC), ensuring predictable, scalable performance for heterogeneous and memorybound AI workloads. 
• A highly performant and reliable, Ethernet scaleup interconnect, featuring an integrated on-die NIC with 2.8 TB/s (bi-directional) of bandwidth, advanced transportprotocol enabling a 2 tier scale up network and topology optimizations to deliver highbandwidth, lowlatency communication across a cluster of 6,144 accelerators.  

A closer look at Maia 200 reveals the architectural advancements and system‑level innovations purpose‑built for inference that enable its industry‑leading efficiency.  

Maia 200 Architecture Overview 

Maia accelerators are organized around a hierarchical micro-architecture. At the foundation of this hierarchy is the tile, the smallest autonomous unit of compute and local storage. Each tile integrates two complementary execution engines: a Tile Tensor Unit (TTU) for high-throughput matrix multiply and convolution, and a Tile Vector Processor (TVP) as a highly programmable SIMD engine. These engines are fed by multi-banked Tile SRAM (TSRAM) and a tile-level DMA subsystem that is responsible for moving data into and out of that SRAM without stalling the compute pipeline. A lightweight Tile Control Processor (TCP) runs the low-level code emitted by the software stack and orchestrates TTU and DMA work issuance, while hardware semaphores provide fine-grained synchronization between data movement and compute.

Maia silicon on-chip innovation

Multiple tiles compose into a cluster, which introduces a second tier of shared locality and coordinated movement. Each cluster contains a large multi-banked Cluster SRAM (CSRAM) accessible across the tiles in that cluster, along with a dedicated cluster DMA subsystem that stages traffic between CSRAM and co-packaged High Bandwidth Memory (HBM). A dedicated cluster core provides the control and synchronization needed to coordinate multi-tile execution, and the full SoC is built by instantiating multiple clusters. Because building at scale requires not just peak performance but manufacturability, the architecture also incorporates redundancy schemes for both tiles and SRAM to improve yield while preserving the hierarchical programming and execution model. 

Maia accelerators feature a highly optimized data movement infrastructure, centered around its Direct Memory Access (DMA) subsystem coupled with a hierarchical Network-on-Chip (NoC). The DMA engines are architected for multichannel, high-bandwidth transfer and support 1D/2D/3D strided movement, enabling common ML tensor layouts to be moved efficiently between on-chip SRAM, HBM, and external interfaces while overlapping data movement with compute. Meanwhile, the NoC provides scalable, low-latency communication across clusters and memory subsystems and supports both unicast and multicast transfers—an important capability for distributing tensor blocks and coordinating parallel execution. To further improve effective memory efficiency, Maia supports multiple narrow-precision data types as storage formats in both HBM and SRAM and employs hardware-based data casting to convert storage types to compute types at line rate so that movement and execution remain tightly coupled. 

For communication beyond the chip, Maia 200 integrates a high‑performance NIC and an Ethernet‑based scale‑up interconnect using an optimized AI Transport Layer (ATL) protocol to deliver scalable, low‑latency communication across nodes. The on‑die NIC provides 1.4 TB/s unidirectional (2.8 TB/s bidirectional) I/O bandwidth, eliminating the power and cost overhead of external NICs while enabling efficient scaling to 6,144 accelerators within a two‑tier scale‑up domain. ATL operates end‑to‑end over standard Ethernet, supporting a commodity, multi‑vendor switching ecosystem, while layering on innovations such as packet spraying, multipath routing, and congestion‑resistant flow control built directly into the transport layer to maximize throughput and stability.

Optimized Tensor Core for Narrow Precision Data Types 

As AI models continue to grow in size and complexity, achieving cost‑effective inference increasingly depends on exploiting narrow‑precision arithmetic and reducing memory footprints to improve performance and efficiency. Industry results consistently show that formats such as FP4 can maintain robust model accuracy for inference while significantly reducing computational and memory requirements. 

Maia 200 is architected from the ground up for narrow‑precision execution. Its Tile Tensor Unit (TTU) is optimized for matrix multiplication in FP8, FP6, and FP4, and supports mixed‑precision modes such as FP8 activations multiplied by FP4 weights to maximize throughput without compromising accuracy. Complementing this, the Tile Vector Processor (TVP) delivers FP8 compute alongside BF16, FP16, and FP32, providing flexibility for layers or operators that benefit from higher precision. An integrated reshaper up‑converts low‑precision formats at line rate prior to computation, ensuring seamless dataflow without introducing bottlenecks. 

Notably, FP4 throughput on Maia 200 is 2× that of FP8, and 8× that of BF16, enabling substantial gains in tokens‑per‑second and performance‑per‑watt for inference‑centric workloads. 

A Reimagined Memory Subsystem  

A defining feature of Maia 200’s architecture is its advanced memory hierarchy, engineered to optimize data movement and sustain high utilization across diverse inference workloads. Maia 200 integrates 272 MB of on‑die SRAM partitioned into multi‑tier Cluster‑level SRAM (CSRAM) and Tile‑level SRAM (TSRAM). This substantial on‑die memory resource enables a wide range of low‑latency, bandwidth‑efficient data‑management strategies. Both CSRAM and TSRAM are fully software‑managed, allowing developers—or the compiler/runtime—to deterministically place and pin data for precise control of locality and movement. 

For example, a primary use case for CSRAM is pinning critical working sets within cluster‑local memory. Keeping frequently accessed data resident on‑chip provides predictable low‑latency access, reduces dependence on higher‑latency memory tiers, and improves deterministic execution. More broadly, the on‑die SRAM hierarchy allows programmers to buffer, stage, and pin data in ways that significantly optimize dataflow patterns across kernel types. Examples include: 

• GEMM kernels can retain intermediate matrix tiles in TSRAM, boosting arithmetic intensity by eliminating round‑trips to HBM or even CSRAM. 

• Attention kernels can pin Q/O tensors, K/V tensors, and partial Q·K products as much as possible in TSRAM, minimizing data‑movement overhead throughout the attention pipeline. 

• Collective‑communication kernels can buffer full payloads in CSRAM while accumulation proceeds in TSRAM, reducing pressure on HBM and preventing bandwidth collapse during multi‑node operations. 

• Cross‑kernel pipelines benefit from CSRAM as a transient buffer between stages, enabling tightly coupled, high‑throughput kernel chaining with fewer stalls particularly valuable for workloads with high kernel density or complex operator fusion. 

Together, these capabilities allow Maia 200 to maintain high compute efficiency and deterministic performance, even as model architectures and sequence lengths grow increasingly demanding. 

An Efficient Data‑Movement Fabric: Specialized DMA Engines and a Custom On‑Chip Interconnect 

Sustained inference utilization on Maia 200 depends on the ability to move data predictably and efficiently among compute tiles, on‑die SRAM, HBM, and I/O. Because inference performance is often bounded by data movement rather than peak FLOPs, the interconnect must support high‑throughput tensor transfers (broadcast, gather, reduce, scatter) while also ensuring low‑latency delivery of synchronization and control signals. Maia 200 addresses this challenge with a custom Network‑on‑Chip (NOC) designed explicitly for inference‑centric dataflow. 

At the chip level, the NOC forms a mesh network spanning all clusters, tiles, memory controllers, and I/O units. It is segmented into multiple logical planes—or virtual fabrics—including a high‑bandwidth data plane for large tensor transfers and a dedicated control plane for interrupts, synchronization, and small messages. This separation ensures that latency‑critical control traffic is never blocked behind bulk data transfers, a key requirement when hundreds of tiles, DMA engines, and controllers operate concurrently. 

Maia 200’s on‑chip fabric introduces several inference‑oriented innovations: 

• Efficient HBM‑to‑cluster broadcast: Hierarchical data movement allows tensors to be fetched once from HBM and fanned out to multiple CSRAM, avoiding redundant HBM reads and improving energy efficiency. 

• Localized high‑bandwidth cluster traffic: High-bandwidth cluster‑local fabrics keep the hottest data movement within the cluster, enabling common inference patterns—such as intra‑layer reductions, scratchpad exchanges, and small collectives—to complete within the cluster without repeatedly traversing global links. 

• Tile‑to‑tile SRAM access: Within a cluster, the fabric allows Tile DMAs and vector units to directly read and write peer tile SRAMs, enabling efficient broadcasts, reductions, and shared‑state updates without engaging HBM and CSRAM. 

• Quality‑of‑Service for critical traffic: QoS mechanisms in both the fabric and memory controllers prioritize urgent, low‑latency messages such as synchronization signals or small inference outputs ensuring they are not delayed by bulk tensor transfers. 

• Fail‑safe management plane: By isolating control and telemetry traffic from the data path, Maia 200 maintains a reliable, always‑available management channel—essential for recovery, coordination, and monitoring in large‑scale inference deployments. 

Complementing the NOC, Maia 200 implements a hierarchy of specialized DMA engines tailored for AI dataflow. Tile DMAs handle fine‑grained transfers between TSRAM and CSRAM; Cluster DMAs shuttle data between CSRAM and HBM or across clusters; and Network DMAs manage send/receive paths for off‑chip links. This layered DMA architecture enables concurrent, overlapped transfers across memory tiers and across nodes, ensuring compute tiles remain well‑fed under diverse workload conditions. 

Together, the custom NOC and multi‑tier DMA hierarchy form a data‑movement subsystem purpose‑built for inference—high‑bandwidth for tensors, low‑latency for control, localized when possible, prioritized when necessary, and efficiently coordinated across the entire chip. This architecture is fundamental to Maia 200’s ability to sustain high utilization across varied and increasingly complex AI workloads. 

A Highly Performant and Reliable 2 Tier ScaleUp Interconnect with An Innovative AI Transport Layer 

Maia 200 incorporates an integrated NIC and a high-performance Ethernet based scaleup interconnect built around Microsoft’s AI Transport Layer (ATL) protocol to enable scalable, low latency chip-to-chip communication across 6,144 Maia accelerators arranged in a two-tier topology. 

Scale‑up networking was approached as a full‑stack solution, architecting the interconnect as a set of well-defined layers co-optimized end-to-end for performance-per-dollar. The design emphasizes predictable latency, full bandwidth utilization, and software defined flexibility, while leveraging the robustness and multivendor support of the commodity Ethernet switch ecosystem. 

A foundational innovation in Maia 200’s interconnect is the on-die integrated NIC and its close coupling with both the ATL protocol engine and the Network DMA. This custom, inhouse network controller is engineered for very low power and area, enabling features such as packet spraying, multipath routing, and congestionresistant flow control directly in the transport layer to maximize throughput and stability. Together, these elements enable a two-tier scaleup fabric optimized for largescale inference workloads, providing tightly coupled communication both within and across racks.

Many accelerator systems rely on allswitched scaleup fabrics, where even local tensorparallel traffic must traverse external switches. This approach forces most collective operations onto shared switch paths, adding hop latency and power and requiring significant port and cabling overprovisioning to sustain worstcase alltoall patterns. Maia 200 avoids these inefficiencies through the Fully Connected Quad (FCQ): groups of four accelerators connected via switchless, direct links. This intranode topology delivers significantly faster tensorparallel communication without relying on an external switch and provides a superior Perf/$ and Perf/W balance for both compute and collective I/O. 

Beyond the FCQ domain, the switched tier extends connectivity to 6,144 accelerators, enabling very large inference models to be sharded across nodes while preserving communication efficiency—without depending on external NICs and scaleout network. This architecture offers three major benefits: 

1. Bandwidth optimizations and reduced overhead 
   High intensity tensor parallel traffic, KV updates, and partial activations remain localized within FCQ groups, while switches handle lighter weight cross domain collectives. 
2. Multirack inference at scale without trainingclass cost 
   The design avoids the power, complexity, and fleetcost burden of scaleout network while still enabling hyperscale inference topologies under practical power envelopes. 
3. Workloadaligned network behavior 
   Modern inference workloads require moderate synchronization—not the extreme alltoall pressure of training. The twotier architecture meets these needs without overengineering the fabric, while still delivering high throughput and low latency for production inference deployments.

The result is a scaleup network that is highperformance, reliable, and right sized achieving the bandwidth, latency, and efficiency targets essential for largescale inference while remaining cost and powerefficient for hyperscale deployment. 

At the top of the scaleup hardware stack is the collective communication layer, which forms the interface between deeplearning frameworks (e.g., PyTorch, TensorFlow) and the underlying hardware. Maia 200 uses the Microsoft Collective Communication Library (MCCL), whose algorithms are codesigned with Maia’s hardware to deliver optimal scaleup performance for specific workload shapes. 

Key areas of innovation in MCCL include: 

• Compute–I/O overlap to hide synchronization overhead and minimize pipeline bubbles. 

• Hierarchical collectives reducing network traffic, lowering latency, and minimizing incast. 

• Dynamic algorithmic selection tuned to tensor sizes and communication patterns. 

• I/O latency hiding through pipelined and predictive scheduling. 

Together, the interconnect hardware and MCCL software deliver a tightly integrated, inferenceoptimized scaleup platform capable of supporting the next generation of largescale, lowlatency AI deployments. 

Maia 200 System: Azure‑Integrated, Cloud‑Native by Design

The Maia 200 system is engineered as a fully Azure‑native platform, tightly integrated into the same cloud infrastructure that powers Microsoft’s largest AI and GPU fleets. At the hardware layer, Maia 200 is co‑designed with Azure’s third‑party GPU systems, adhering to a standardized rack, power, and mechanical architecture that simplifies deployment, improves serviceability, and allows heterogeneous accelerators to coexist within the same datacenter footprint. This alignment enables Azure to operate Maia 200 at hyperscale without requiring bespoke infrastructure or specialized site configurations. 

Thermal design is equally modular. Maia 200 supports deployments in both air and liquid cooled datacenters, including a second‑generation liquid‑cooling sidecar designed for high‑density racks and thermally constrained environments. This ensures broad deployability and fungibility across both legacy air-cooled and next‑generation liquid cooled datacenters while maintaining consistent performance under sustained workloads. 

Operationally, Maia 200 integrates with Azure’s native control plane, inheriting the same lifecycle, availability, and reliability guarantees as other Azure compute services. Firmware rollouts, fault detection and health monitoring are all performed through impactless, fleet‑wide management workflows, minimizing disruption and ensuring consistent service levels. This tight control‑plane integration also enables automated node bring‑up, safe in‑place upgrades, and coordinated multi‑rack maintenance—capabilities essential for large‑scale inference deployments.  

Maia 200

Maia 200 will be part of our heterogenous AI infrastructure supporting multiple models, including the latest GPT-5.2 models from OpenAI, to power AI workloads in Microsoft Foundry and Microsoft 365 Copilot.

 It will be fully integrated into Azure allowing models and workloads to be scheduled, partitioned, and monitored using the same tooling that supports Azure’s GPU fleets. This ensures portability across hardware types and allows service operators to optimize for perf/$, latency, or capacity without rewriting orchestration logic. 

Together, these system‑level capabilities make Maia 200 not just an highly efficient inference accelerator, but a cloud‑native compute building block, integrated seamlessly into Azure’s global AI infrastructure and optimized for reliable, large‑scale, multi‑tenant operation. 

Maia 200 Software Stack and Developer Toolchain: A Cloud‑Native Platform for High‑Performance Inference 

The Maia 200 software stack brings together a fully Azure‑integrated inference platform and a modern, developer‑oriented SDK built to deliver performance at scale. It is designed so cloud developers can adopt Maia seamlessly, leveraging familiar tooling while accessing low‑level control when needed for peak efficiency.  

For developers, the Maia SDK provides a comprehensive toolchain for building, optimizing, and deploying both open source and proprietary models on Maia hardware. Workflows begin naturally with PyTorch, and developers can choose the level of abstraction required: 

• use the Maia Triton compiler for rapid kernel generation, 

• rely on highly optimized kernel libraries tuned for Maia’s tile‑ and cluster‑based architecture, or 

• target Microsoft’s Nested Parallel Language (NPL) for explicit control of data movement, SRAM placement, and parallel execution to reach near–peak utilization.

Maia software stack

The SDK includes a full simulator, compiler pipeline, profiler, debugger, and a robust quantization and validation suite, enabling teams to prototype models before silicon availability, diagnose performance bottlenecks with fine granularity, and tune kernels for optimal execution across the Maia stack. 

Together, the Maia inference stack and SDK form a unified platform that accelerates model bring‑up, simplifies performance optimization, and makes high‑performance inference a first‑class, cloud‑native development experience. 

In conclusion, with Maia 200, we demonstrate that leadership in AI infrastructure comes from unified system and workload optimizations across the entire stack — AI models, software toolchain and orchestration, custom silicon, networking, rack‑scale architecture, and datacenter infrastructure. Maia 200 embodies this principle, delivering 30% better performance per dollar than the latest generation hardware in our fleet today with an architecture that is purpose‑built for efficiency at scale. It represents a decisive step in advancing the world’s most capable, efficient, and scalable cloud platform, and forms the foundation for Microsoft’s AI future.