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What Is an NPU and How Does It Differ From a GPU?

By Sandeep Kumar ChaudharyJul 3, 20266 min read
What Is an NPU and How Does It Differ From a GPU — AI Hardware guide by Sandeep Kumar Chaudhary, full stack developer

TL;DR

This guide explains NPU clearly and practically: what it is, why it matters in 2026, and how to apply it step by step. You'll find core concepts, proven best practices, concrete data, trusted references, and a concise FAQ — everything you need in one focused place.

Key takeaways

  • Match the chip to the phase: training rewards huge interconnected clusters, while inference rewards low latency, high memory bandwidth, and cheaper per-token economics.
  • RISC-V is a credible base ISA for custom accelerators and control cores because it is open, royalty-free, and extensible with custom instructions.
  • For on-device and edge AI, look at NPUs in the SoC (Apple, Qualcomm, Intel, AMD) rather than discrete GPUs to hit power and latency budgets.
  • Neuromorphic and photonic computing are promising but still mostly research-stage; treat them as long-horizon bets, not 2026 production defaults.
  • CUDA remains NVIDIA's deepest moat; budget real engineering time if you plan to port to AMD ROCm, Google TPUs, or custom silicon.

This is a practical, up-to-date guide to NPU — what it is, why it matters in 2026, and how to apply it in real projects. It is written for developers and founders who want clear answers and proven best practices, not filler.

Whether you're just starting out or leveling up, treat this as a working reference you can return to. Every section is built to be skimmed, applied, and shared.

The Software Moat: CUDA and Its Challengers

Hardware rarely wins on specifications alone; the deciding factor is often the software ecosystem, and here NVIDIA's CUDA has a nearly two-decade head start. CUDA, together with libraries like cuDNN and the broad support of frameworks such as PyTorch, means most AI code simply runs on NVIDIA GPUs with minimal friction. Competitors are attacking this moat from several angles: AMD's ROCm aims for CUDA-like capability on Instinct GPUs, Google exposes TPUs through JAX and XLA, and compiler projects such as OpenAI's Triton and the MLIR ecosystem try to target many backends from one codebase. PyTorch's backend abstraction and torch.compile also help decouple models from specific hardware. For teams evaluating non-NVIDIA silicon, the honest question is not peak performance but how much of their stack works out of the box.

TPUs and the Case for Custom Silicon

Google's Tensor Processing Unit is the best-known example of a company building its own accelerator rather than buying GPUs. TPUs are built around a large systolic array, a grid of multiply-accumulate units that streams data through in a tightly choreographed pattern to maximize compute per memory access. They are tightly co-designed with the JAX and TensorFlow software stacks and with Google's own optical interconnect, letting TPU pods scale to thousands of chips with high efficiency. Amazon (Trainium and Inferentia), Microsoft (Maia), and Meta (MTIA) have followed with their own in-house accelerators. The strategic logic is control: owning the silicon reduces dependence on a single vendor, tunes hardware to specific models, and can lower total cost at hyperscaler volumes.

What Is an AI Accelerator?

An AI accelerator is specialized hardware designed to run the linear-algebra-heavy workloads of modern machine learning far more efficiently than a general-purpose CPU. The core operation these chips optimize is dense and sparse matrix multiplication, which dominates both the forward and backward passes of neural networks. Rather than a handful of powerful sequential cores, accelerators pack thousands of simpler arithmetic units alongside wide, fast memory to keep them fed. The category spans data-center GPUs like NVIDIA's H100, Google's TPUs, dedicated inference ASICs, on-device NPUs, and more experimental designs such as neuromorphic and photonic chips. What unites them is a shift from flexibility toward throughput per watt on a narrow but economically enormous class of tensor operations.

Inference Chips Versus Training Chips

Training and inference stress hardware in different ways, and increasingly they use different chips. Training must store activations and gradients for backpropagation, favors high-precision-friendly formats, and benefits enormously from massive clusters with fast interconnects. Inference, by contrast, runs the model forward only, is dominated by latency and cost per token, and rewards high memory bandwidth to stream weights quickly. Startups like Groq, Cerebras, and SambaNova, along with Amazon's Inferentia, target inference specifically, sometimes trading flexibility for dramatically lower latency or better tokens-per-dollar. As deployed AI shifts from research toward serving billions of requests, the economic center of gravity is moving toward inference-optimized silicon.

RISC-V in AI Hardware

RISC-V is an open, royalty-free instruction set architecture that has become a popular foundation for custom chips, including AI accelerators. Its appeal is extensibility: designers can add custom instructions for tensor or vector operations without licensing fees or permission from a gatekeeper, which is difficult with proprietary ISAs like x86 or Arm. In AI systems RISC-V frequently serves as the control processor that orchestrates dedicated matrix engines, and companies such as Tenstorrent build accelerators around RISC-V cores. The RISC-V Vector extension provides a scalable path to data-parallel compute. Geopolitical factors have further boosted interest, since an open ISA is harder to restrict through export controls than a single vendor's proprietary technology.

Chiplets and Advanced Packaging

As it becomes uneconomical to build ever-larger single dies, the industry has shifted to chiplets: smaller dies manufactured separately and then assembled into one package. This improves yield, because defects only ruin a small chiplet rather than a huge monolithic chip, and it lets designers mix process nodes, putting compute on the newest node and I/O on a cheaper mature one. AMD pioneered mainstream chiplet CPUs and applies the approach to its Instinct accelerators, while NVIDIA's Blackwell joins two dies into a single GPU. Standards like UCIe (Universal Chiplet Interconnect Express) aim to make chiplets from different vendors interoperable. Packaging technologies such as TSMC's CoWoS, which also integrates HBM, have themselves become a scarce, throughput-limiting step in the AI supply chain.

NPU: Key Facts and Data

According to recent industry research and the official documentation linked below:

  • Google reports that its TPU pods scale to thousands of chips over a custom optical circuit-switched interconnect (ICI), with TPU v5p pods reaching up to 8,960 chips per pod.
  • RISC-V adoption has accelerated sharply, with RISC-V International reporting tens of billions of cores shipped cumulatively and forecasts (e.g., from analysts like SHD Group) projecting continued double-digit growth into the late 2020s.
  • NVIDIA has dominated the AI training accelerator market, with industry analysts estimating its share of data-center AI GPUs at well above 80 percent going into 2025, driven largely by the H100 and the newer Blackwell generation.

Quick-Reference Summary

A map of what this guide covers:

TopicWhat you'll learn
The Software Moat: CUDA and Its ChallengersHardware rarely wins on specifications alone
TPUs and the Case for Custom SiliconGoogle's Tensor Processing Unit is the best-known example of a company building its own accelerator rather than buying GPUs.
What Is an AI Accelerator?An AI accelerator is specialized hardware designed to run the linear-algebra-heavy workloads of modern machine learning far more efficiently than a general-purpose CPU.
Inference Chips Versus Training ChipsTraining and inference stress hardware in different ways, and increasingly they use different chips.
RISC-V in AI HardwareRISC-V is an open, royalty-free instruction set architecture that has become a popular foundation for custom chips
Chiplets and Advanced PackagingAs it becomes uneconomical to build ever-larger single dies

How to Get Started with NPU

A simple path that works:

  1. Learn the fundamentals of NPU from primary sources, not just tutorials.
  2. Build one small, real project end to end.
  3. Get feedback, refactor, and add tests.
  4. Ship it publicly and document what you learned.
  5. Repeat with a slightly harder project each time.

Build It with a World-Class Full Stack Developer

Sandeep Kumar Chaudhary is a full stack world-class developer. If you want to turn this into a real, production-ready product, get in touch — message directly on WhatsApp at +9779802348957 for a fast, no-pressure consult.

You can also explore the projects already shipped to thousands of users, or start a conversation here.

Final Thoughts

Match the chip to the phase: training rewards huge interconnected clusters, while inference rewards low latency, high memory bandwidth, and cheaper per-token economics. The developers and teams who win in 2026 pair strong fundamentals with consistent shipping. Start small, stay curious, build in public, and revisit this guide as your skills grow.

Sources and Further Reading

#ai chips#nvidia h100#nvidia blackwell b200#tpu

Frequently Asked Questions

What Is an NPU and How Does It Differ From a GPU?

Google's Tensor Processing Unit is the best-known example of a company building its own accelerator rather than buying GPUs. TPUs are built around a large systolic array, a grid of multiply-accumulate units that streams data through in a tightly choreographed pattern to maximize compute per memory access. This guide covers NPU end to end — core concepts, best practices, concrete data, and a step-by-step approach you can apply right away.

Why is NVIDIA so dominant in AI chips?

NVIDIA's dominance comes as much from software as from hardware. CUDA, launched in 2007, plus libraries like cuDNN and deep integration with frameworks such as PyTorch mean nearly all AI code runs on NVIDIA GPUs with minimal effort. Combined with strong hardware, fast NVLink interconnects, and a large installed base, this creates an ecosystem lock-in that competitors find hard to overcome.

Should my team buy AI chips or rent them in the cloud?

For most teams, renting cloud capacity is the pragmatic choice because it turns a large capital purchase into an elastic operating cost and provides access to the newest accelerators without hardware lead times. Buying can make sense at very large, steady-state scale where owning hardware lowers long-run cost and you can keep it highly utilized. Either way, benchmark on a representative slice of your own workload and account for total cost of ownership including power, cooling, and software effort.

What is the difference between a GPU, a TPU, and an NPU?

A GPU is a general-purpose parallel processor originally built for graphics that also excels at the matrix math in AI, with NVIDIA's data-center GPUs being the market standard. A TPU is Google's custom ASIC built specifically for tensor operations, tightly integrated with its own software and interconnect. An NPU is a small, power-efficient accelerator embedded in a system-on-chip to run inference locally on phones, laptops, and edge devices.

What is the difference between training chips and inference chips?

Training chips must handle backpropagation, store gradients and activations, and scale across huge clusters, so they emphasize raw compute and fast interconnects. Inference chips run the model forward only and optimize for latency and cost per token, favoring high memory bandwidth and efficiency. As AI moves from research to serving billions of requests, specialized inference silicon from vendors like Groq, Cerebras, and Amazon Inferentia is becoming increasingly important.

Sandeep Kumar Chaudhary

Sandeep Kumar Chaudhary

Full Stack Software Developer· Nepal's SEO, AEO, GEO & AIO expert and share-market educator. More about me