macrostack

Layer 2 · head to head

AWS Trainium 3 vs AMD Instinct MI355X

The two most credible cost-per-token challengers, one locked to a cloud, one not.

AWS Trainium 3AMD Instinct MI355X
Can you get itCannot be bought. Exists only inside one cloud, so choosing it is choosing that cloud.Rentable by the hour from multiple clouds; purchasable at scale.
Memory144 GB HBM3e per chip288 GB HBM3E
Bandwidth4.9 TB/s per chip8 TB/s
Compute2.52 PFLOPS FP8 per chip~10 PFLOPS sparse FP4
PowerNot publishedNot consistently published
InterconnectNeuronLinkInfinity Fabric
SoftwareAWS Neuron SDKROCm
Workloadbothboth

AWS Trainium 3

For: Dense training and inference on AWS. Unlike TPU v7 it is designed for both, which makes it the more honest Trainium-vs-TPU comparison.

The catch: AWS-only, and the Neuron SDK is a third software ecosystem to support alongside CUDA and ROCm. Model coverage is the question to ask, not FLOPS.

Economics: Independent analysis has singled out Trainium as the NVIDIA alternative that actually pays off on cost per token — largely because AWS prices it to move.

AMD Instinct MI355X

For: Memory-bound inference. 288 GB against Blackwell's 192 GB is the cleanest technical argument AMD has made in a decade.

The catch: ROCm, not CUDA. The gap has narrowed sharply but it is still the reason procurement teams say no, and porting cost is real.

Economics: AMD positions this as the best price-per-token part for inference at scale, and claims 2.6x H100 inference throughput on Llama 3.1 405B for the MI350X.

Before either — can you power it?

Not published against Not consistently published. In 2026 that comparison usually matters more than the FLOPS one: the US interconnection queue exceeds 2,600 GW with waits approaching five years, and roughly 80% of projects withdraw before energising.

Layer 1 — Energy · Nuclear vs gas · Direct-to-chip cooling

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Specifications verified 2026-09-09. We take no commission at this layer, on either part.

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