AMD Instinct MI350X / MI355X (CDNA 4)
Overview
The AMD Instinct MI350 series, launched on June 12, 2025, is AMD's latest flagship AI accelerator, based on the CDNA 4 architecture. It features 288GB HBM3e memory, 8 TB/s bandwidth, and up to 2.5 PFLOPS FP16 compute. The MI350 introduces native MXFP4 and MXFP6 data type support, targeting NVIDIA Blackwell.
Core Specifications
| Item | MI350X | MI355X |
|---|
| Architecture | CDNA 4 | CDNA 4 |
| Memory | 288 GB HBM3e | 288 GB HBM3e |
| Bandwidth | 8 TB/s | 8 TB/s |
| LLC | 256 MB | 256 MB |
| FP64 | 72.1 TFLOPS | 78.6 TFLOPS |
| FP16 Matrix | 2.3 PFLOPS | 2.5 PFLOPS |
| MXFP8 | 4.6 PFLOPS | 5.0 PFLOPS |
| MXFP6 | 9.2 PFLOPS | 10.1 PFLOPS |
| MXFP4 | 9.2 PFLOPS | 10.1 PFLOPS |
| TDP | 750 W | 1,400 W (liquid cooling) |
| Cooling | Air | Liquid (DLC) |
| PCIe | Gen 5 | Gen 5 |
| Platform | Configuration |
|---|
| 8× MI350X | 2.3 TB HBM3E, 64 TB/s aggregate bandwidth, 18.5 PFLOPS FP16 |
| 8× MI355X | 2.3 TB HBM3E, 64 TB/s aggregate bandwidth, 20.1 PFLOPS FP16 |
| Hyperscale | 128× liquid-cooled MI355X (16 UBB 8-card trays) |
MI350 vs Blackwell Comparison
| Metric | MI355X | B200 | GB200 (186GB) |
|---|
| Memory | 288 GB | 192 GB | 186 GB |
| Bandwidth | 8 TB/s | 8 TB/s | 8 TB/s |
| FP8 Compute | 10.1 PFLOPS (MXFP6) | 9 PFLOPS | 9 PFLOPS |
| FP4 Support | ✓ MXFP4 | ✓ Native | ✓ Native |
Key difference: MI355X has more memory (+50%), while B200 has higher FP4 compute (18 PFLOPS vs MI355X 10.1 PFLOPS).
Key Features
- Native MXFP4 / MXFP6 support: Micro-scaled floating-point formats
- 4× previous-gen AI compute (AMD official)
- 35× previous-gen inference performance
- CDNA 4 architecture (N3P process XCD)
- ROCm 7: New
pip install rocm simplified installation
Use Cases
- Trillion-parameter LLM training and inference
- Long-context inference
- MoE models (Mixtral, Llama 4)
- HPC and AI mixed workloads