What Are TPUs and When Should You Use Them Over GPUs?

By Sandeep Kumar ChaudharyJul 6, 20266 min read

TL;DR

Here is a clear, practical guide to tpus: the fundamentals, the best practices that actually move the needle, common mistakes to avoid, concrete data points, and a short FAQ. Everything is structured so you can apply it to real projects today.

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.
Chiplets are now mainstream: assume future high-end accelerators are multi-die packages, which changes yield, cost, and thermal reasoning.
RISC-V is a credible base ISA for custom accelerators and control cores because it is open, royalty-free, and extensible with custom instructions.
CUDA remains NVIDIA's deepest moat; budget real engineering time if you plan to port to AMD ROCm, Google TPUs, or custom silicon.
Lower-precision formats like FP8 and FP4 are the fastest lever for throughput, but validate accuracy on your own eval set before shipping quantized models.

This is a practical, up-to-date guide to Tpus — 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.

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.

Choosing and Adopting AI Hardware

Selecting AI hardware starts with being honest about the workload: training a foundation model, fine-tuning, and serving inference at scale have very different optimal chips. For most teams the pragmatic path is renting capacity from cloud providers rather than buying, which turns a large capital commitment into an elastic operating cost and grants access to the newest accelerators. Key evaluation criteria include memory capacity and bandwidth, supported numerical formats, interconnect bandwidth for multi-chip scaling, and, crucially, software maturity for your framework. It is wise to benchmark on a representative slice of your own model and data rather than trusting vendor peak numbers, and to watch total cost of ownership including power and cooling. Finally, avoid over-committing to exotic hardware whose ecosystem could strand your investment if the vendor stumbles.

Photonic Computing

Photonic computing performs computation using light rather than electrical currents, exploiting the physics of optics to do certain operations, especially matrix multiplication, with potentially very low energy and latency. Because light can carry many signals in parallel across different wavelengths and does not dissipate energy the way charging and discharging transistors does, photonics is attractive for the linear-algebra core of neural networks. Companies such as Lightmatter and Lightelligence are building photonic accelerators and, notably, optical interconnects that move data between chips using light. In fact, photonics is arriving first as interconnect, since co-packaged optics can relieve the communication bottleneck in large clusters. Pure photonic compute still faces challenges around analog precision, data conversion overhead, and integration, keeping it earlier-stage than the interconnect use case.

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.

NPUs and On-Device Inference

A Neural Processing Unit is a compact accelerator integrated into a system-on-chip to run inference locally on phones, laptops, and embedded devices. Apple's Neural Engine, Qualcomm's Hexagon NPU, and the NPUs in Intel Core Ultra and AMD Ryzen AI processors all target the same goal: run models within a few watts and without a round trip to the cloud. This matters for latency-sensitive features, offline capability, and privacy, since data never leaves the device. NPU performance is often quoted in TOPS (trillions of operations per second) at low precision, and the recent Copilot+ PC category set an informal bar around 40 TOPS for on-device AI. The tradeoff is a tight power and memory envelope, so on-device models are heavily quantized and pruned.

Tpus: Key Facts and Data

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

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.
The Hopper-based H100 SXM offers 80 GB of HBM3 memory delivering roughly 3.35 TB/s of bandwidth, while the Blackwell B200 pairs two reticle-limited dies into one package with 192 GB of HBM3e and around 8 TB/s of bandwidth.
As of 2025, high-bandwidth memory is a primary bottleneck for AI accelerators, and SK hynix, Samsung, and Micron are the three suppliers producing HBM3e stacks, with SK hynix widely reported as the leading HBM vendor.

Quick-Reference Summary

A map of what this guide covers:

Topic	What you'll learn
Inference Chips Versus Training Chips	Training and inference stress hardware in different ways, and increasingly they use different chips.
Choosing and Adopting AI Hardware	Selecting AI hardware starts with being honest about the workload
Photonic Computing	Photonic computing performs computation using light rather than electrical currents
RISC-V in AI Hardware	RISC-V is an open, royalty-free instruction set architecture that has become a popular foundation for custom chips
Chiplets and Advanced Packaging	As it becomes uneconomical to build ever-larger single dies
NPUs and On-Device Inference	A Neural Processing Unit is a compact accelerator integrated into a system-on-chip to run inference locally on phones

How to Get Started with Tpus

A simple path that works:

Learn the fundamentals of Tpus from primary sources, not just tutorials.
Build one small, real project end to end.
Get feedback, refactor, and add tests.
Ship it publicly and document what you learned.
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