MI325X vs MI355X

CDNA 3vsCDNA 4Updated 35 days ago

The MI355X stands as the clear winner for prevalent AI tasks like LLM training and inference: 2300 TFLOPS FP16/FP32 and 288 GB VRAM outperform the MI325X's 1307 TFLOPS and 256 GB, enabling larger models and quicker iterations within the shared 750W TDP envelope.

Specifications Compared

SpecMI325XMI355X
TDP750W750W
VRAM256 GB288 GB
Memory TypeHBM3eHBM3e
ArchitectureCDNA 3CDNA 4
Form FactorsOAMOAM
InterconnectInfinity FabricInfinity Fabric
FP8 Performance2,614 TFLOPS4,600 TFLOPS
FP16 Performance1,307 TFLOPS2,300 TFLOPS
FP32 Performance1307 TFLOPS2300 TFLOPS
FP64 Performance40.9 TFLOPS72 TFLOPS
INT8 Performance2,614 TOPS4,600 TOPS
Memory Bandwidth6,000 GB/s8,000 GB/s

Performance Analysis

Compute specifications highlight the MI355X's advantage: 2300 TFLOPS in FP16 and FP32 surpasses the MI325X's 1307 TFLOPS by 76 percent. This uplift accelerates deep learning training, where FP16 precision dominates, and FP32 supports scientific computations; inference benefits similarly from the FP8 jump to 4600 TFLOPS from 2614 TFLOPS. Both GPUs equalize FP16 and FP32 rates, optimizing mixed-precision workflows without bottlenecks.

Memory differences impact real-world scalability: 288 GB VRAM on the MI355X versus 256 GB enables larger batch sizes in LLM training, fitting models that exceed MI325X limits. Bandwidth at 8000 GB/s, a 33 percent increase over 6000 GB/s, reduces latency in data-intensive tasks like Stable Diffusion generation or large dataset processing. Despite identical 750W TDP, the MI355X delivers higher performance per watt, enhancing efficiency in power-constrained clusters.

These specs position the MI355X for memory-bound inference and training, while the MI325X suffices for moderate workloads without full utilization of peak capacities.

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When to Choose the MI325X

The MI325X fits scenarios prioritizing current availability over maximum performance, as its 2024 CDNA 3 architecture precedes the 2025 MI355X release. Workloads like fine-tuning mid-sized models at 1307 TFLOPS FP16 or those fitting within 256 GB VRAM and 6000 GB/s bandwidth perform adequately without needing the newer generation. Cost-sensitive deployments may favor it if pricing emerges lower, given no live offers for either.

When to Choose the MI355X

The MI355X excels in high-demand AI applications requiring 2300 TFLOPS FP16/FP32 or 288 GB VRAM, such as training massive LLMs. Its 8000 GB/s bandwidth supports larger batches and faster data throughput compared to the MI325X's 6000 GB/s. Future-proofing for CDNA 4 optimizations makes it preferable for inference at 4600 TFLOPS FP8.

Use Cases

LLM Training
MI355X

MI355X provides 2300 TFLOPS FP16 and 288 GB VRAM, supporting larger models and batches than MI325X's 1307 TFLOPS and 256 GB.

LLM Inference
MI355X

FP8 performance at 4600 TFLOPS on MI355X accelerates quantized inference, exceeding MI325X's 2614 TFLOPS for higher throughput.

Fine-tuning
Either

MI325X handles mid-sized models at 1307 TFLOPS FP16 within 256 GB VRAM; MI355X offers headroom at 2300 TFLOPS and 288 GB for larger ones.

Stable Diffusion
MI355X

MI355X's 8000 GB/s bandwidth and 2300 TFLOPS FP16 speed image generation more than MI325X's 6000 GB/s and 1307 TFLOPS.

Scientific Computing
MI355X

FP32 at 2300 TFLOPS on MI355X outperforms MI325X's 1307 TFLOPS, with 288 GB VRAM aiding complex simulations.

Frequently Asked Questions

What is the VRAM capacity of the MI325X versus MI355X?

The MI325X features 256 GB HBM3e VRAM, while the MI355X increases to 288 GB HBM3e. This difference allows the MI355X to accommodate larger AI models. Both use high-bandwidth memory for data center tasks.

How do FP16 performance levels compare between MI325X and MI355X?

MI325X delivers 1307 TFLOPS FP16, compared to 2300 TFLOPS on MI355X, a 76 percent gain. This boosts training and inference speeds. FP32 matches these rates on both GPUs.

Do the MI325X and MI355X have the same power consumption?

Both GPUs maintain a 750W TDP rating. The MI355X achieves higher performance within this limit, improving efficiency. Form factors and interconnects are identical as OAM and Infinity Fabric.

What architectures power the MI325X and MI355X?

MI325X uses CDNA 3 from 2024; MI355X employs CDNA 4 from 2025. These evolutions enhance AI optimizations. Compute specs reflect the generational leap.

Which GPU has higher memory bandwidth?

MI355X offers 8000 GB/s, surpassing MI325X's 6000 GB/s by 33 percent. This aids batch processing in inference. It pairs with greater VRAM capacity.

Are there live pricing offers for MI325X or MI355X?

No live offers exist for either GPU on gpuperhour.com currently. MI325X launched in 2024, MI355X in 2025, affecting availability. Monitor for updates.

Which is cheaper to rent, the MI325X or the MI355X?

Cloud rental prices for both the MI325X and MI355X vary by provider, configuration, and availability. This page shows live pricing from 25+ providers updated every 60 seconds. Scroll to the Live Cloud Pricing section to compare current rates.

How much VRAM does the MI325X have compared to the MI355X?

The MI325X has 256 GB of HBM3e memory. The MI355X has 288 GB of HBM3e memory.

Can I find MI325X and MI355X GPUs available to rent right now?

Yes. This page shows real-time availability across 25+ cloud GPU providers. The Live Cloud Pricing section displays only in-stock offers with current pricing.

What is the main difference between the MI325X and the MI355X?

The MI325X uses the CDNA 3 architecture (2024) while the MI355X uses CDNA 4 (2025). The MI355X delivers 1.8x the FP16 throughput and 1.3x the memory bandwidth of the MI325X.

MI325X vs MI355X: 288GB HBM3e vs 256GB HBM3e | GPUPerHour