Wednesday, June 11th 2025
AMD Instinct MI355X Draws up to 1,400 Watts in OAM Form Factor
Tomorrow evening, AMD will host its "Advancing AI" livestream to introduce the Instinct MI350 series, a new line of GPU accelerators designed for large-scale AI training and inference. First shown in prototype form at ISC 2025 in Hamburg just a day ago, each MI350 card features 288 GB of HBM3E memory, delivering up to 8 TB/s of sustained bandwidth. Customers can choose between the single-card MI350X and the higher-clocked MI355X or opt for a full eight-GPU platform that aggregates to over 2.3 TB of memory. Both chips are built on the CDNA 4 architecture, which now supports four different precision formats: FP16, FP8, FP6, and FP4. The addition of FP6 and FP4 is designed to boost throughput in modern AI workloads, where models of tomorrow with tens of trillions of parameters are trained on FP6 and FP4.
In half-precision tests, the MI350X achieves 4.6 PetaFLOPS on its own and 36.8 PetaFLOPS in eight-GPU platform form, while the MI355X surpasses those numbers, reaching 5.03 PetaFLOPS and just over 40 PetaFLOPS. AMD is also aiming to improve energy efficiency by a factor of thirty compared with its previous generation. The MI350X card runs within a 1,000 Watt power envelope and relies on air cooling, whereas the MI355X steps up to 1,400 Watts and is intended for direct-liquid cooling setups. That 400 Watt increase puts it right at NVIDIA's upcoming GB300 "Grace Blackwell Ultra" superchip, which is also a 1,400 W design. With memory capacity, raw computing, and power efficiency all pushed to new heights, the question remains whether real-world benchmarks will match these ambitious specifications. AMD now only lacks platform scaling beyond eight GPUs, which the Instinct MI400 series will address.
Sources:
ComputerBase, via VideoCardz
In half-precision tests, the MI350X achieves 4.6 PetaFLOPS on its own and 36.8 PetaFLOPS in eight-GPU platform form, while the MI355X surpasses those numbers, reaching 5.03 PetaFLOPS and just over 40 PetaFLOPS. AMD is also aiming to improve energy efficiency by a factor of thirty compared with its previous generation. The MI350X card runs within a 1,000 Watt power envelope and relies on air cooling, whereas the MI355X steps up to 1,400 Watts and is intended for direct-liquid cooling setups. That 400 Watt increase puts it right at NVIDIA's upcoming GB300 "Grace Blackwell Ultra" superchip, which is also a 1,400 W design. With memory capacity, raw computing, and power efficiency all pushed to new heights, the question remains whether real-world benchmarks will match these ambitious specifications. AMD now only lacks platform scaling beyond eight GPUs, which the Instinct MI400 series will address.
10 Comments on AMD Instinct MI355X Draws up to 1,400 Watts in OAM Form Factor
GAA-fet promise to bring down the power consumption at least by 32%, so this means that 1400 watts - 32% = 952watts, thus 448watt difference.
Yeh... I'm such mad that's gaa-fet is not yet here.
If not, then I'm going to buy for my self a mac book pro & Hasta la vista PC & everything related with x86-64.
What pretty much everyone doesn't understand is that these are exascale computing parts and them having such high wattage ratings won't reflect on the desktop PCIe GPUs.
I assume AMD will help the consortium to come up with a new revision in order to standardize those higher TDPs.
Also:Nice joke lol
www.tomshardware.com/pc-components/gpus/amds-instinct-mi355x-accelerator-will-consume-1-400-watts
Each MI355X is rated for ~5 PFLOPS FP16, I know the flops metric is a tired old trope but it's a decent enough account of hardware's raw theoretical performance, and this is a mindblowing number. It's several times faster than something like a RTX 5090. Speaking of which, a 600 W 5090 may sound crazy to most people, but if you look at the raw numbers, you will find the exact same thing going on: the math won't lie ;)
All that AMD is missing is a solid, performant runtime to take this market by storm, they have the hardware already.