Google Reveals Next-Gen TPU Details at Hot Chips 2025

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Google’s Ironwood “Next-Gen TPU” Platform Delivers Significant Uplifts Versus Prior Generation

The 7th generation TPU architecture, named Ironwood, was introduced in April of this year. It is designed to offer 24x the performance of today’s most powerful supercomputers.

In 2022, Google launched its TPU v4, featuring 4096 chips per pod with 32 GB of 1.2 TB/s HBM memory and a compute output of 275 TFLOPs per chip. In 2023, they introduced the TPU v5p with 8960 chips, 95 GB of 2.8 TB/s HBM memory, and 459 TFLOPs of compute output. This year’s Ironwood Superpod offers 9216 chips per pod, 192 GB of 7.4 TB/s HBM memory, and a peak FLOP rate of 4614 TFLOPs per chip – that’s more than a 16x increase over TPU v4.

The core block of the Ironwood system is its SoC (System on Chip). Four Ironwood SoCs are included in an Ironwood PCBA motherboard, which is then implemented inside an Ironwood TPU rack. An Ironwood TPU rack contains 16 such PCBAs arranged like trays to form a 64-chip solution.

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October 8, 2025

The interconnect solution leverages Google’s InterChip Interconnect (ICI), a scale-up network that allows up to 43 blocks of Superpods to be connected using a 1.8 petabyte network. Internal communications are managed by various NICs.

Google offers a suite of racks in the Ironwood Superpod, including:
– The Ironwood Superpod with 144 racks
– Optical switch chassis for scale-up ICI across multiple blocks
– CBU (Cooling Distribution Unit) rack for coolant distribution

Each logical building block consists of a 4x4x4 3D network that is 64 chips or nodes, packaged into a single rack using a 3D Torus layout.

The interconnect employs a hybrid approach with PCB trades, copper passive links to cables, and optical fiber connecting through pad panels. This setup provides flexibility.

At the top of each rack is an upper drip pan for liquid detection, followed by power delivery that includes two domains converting 416V AC to DC using rectifiers. The entire unit features liquid cooling, capable of handling over 100kW in a single run.

That concludes Google’s Ironwood TPU platform presentation at Hot Chips 2025.