Instinct MI355X vs Instinct MI300X
Complete side-by-side comparison of specs, performance, memory, power efficiency, and pricing.
Instinct MI355X
96
Spec Wins
Instinct MI300X
65
Detailed Specifications
Instinct MI355X — Best For
Instinct MI300X — Best For
Who Should Choose Each GPU?
Choose Instinct MI355X if you…
- ✓Need more VRAM (288GB vs 192GB) for large model inference
- ✓Prioritize raw FP8 throughput (4,625 vs 2,614 TFLOPS)
- ✓Running LLM Training workloads
- ✓Running Frontier AI workloads
- ✓Running HPC workloads
Choose Instinct MI300X if you…
- ✓Have power-constrained data centers (750W vs 1400W TDP)
- ✓Working with a tighter CapEx budget (lower list price)
- ✓Running Large Models workloads
- ✓Running Cost-Effective Training workloads
Verdict
The Instinct MI355X and Instinct MI300X target different priorities. The Instinct MI355X's 288GB of HBM3e gives it a clear edge for large-model inference where fitting the full model in VRAM eliminates quantization overhead. For training throughput, the Instinct MI355X's 4,625 FP8 TFLOPS outpaces the Instinct MI300X's 2,614 TFLOPS. Both GPUs use ROCM, so ecosystem switching cost is not a factor. Use our TCO Calculator to model the full 3-year cost difference for your specific utilization and power costs.
Instinct MI355X vs Instinct MI300X: Common Questions
Which is faster, Instinct MI355X or Instinct MI300X?+
In FP8 throughput, the Instinct MI355X leads with 4,625 TFLOPS vs 2,614 TFLOPS. For LLM inference, memory capacity and bandwidth often matter more than raw TFLOPS — the Instinct MI355X has more VRAM (288GB).
Is Instinct MI355X or Instinct MI300X better for LLM training?+
For LLM training at scale, the Instinct MI355X has higher raw throughput. However, the choice also depends on your software stack: Instinct MI300X offers CUDA compatibility with the widest framework support (PyTorch, JAX, TensorRT).
What is the price difference between Instinct MI355X and Instinct MI300X?+
The Instinct MI355X is estimated at $30,000 per unit and the Instinct MI300X at $15,000. Actual pricing varies by vendor, volume, and configuration. Check our Buy page for current reseller pricing.
Which GPU is more power efficient, Instinct MI355X or Instinct MI300X?+
The Instinct MI300X has a lower TDP (750W vs 1400W). Performance-per-watt depends on your workload — for FP8 inference, divide TFLOPS by TDP: Instinct MI355X = 3.3 TFLOPS/W vs Instinct MI300X = 3.5 TFLOPS/W.