Blackwell Ultra B300 vs Instinct MI300X
Complete side-by-side comparison of specs, performance, memory, power efficiency, and pricing.
Blackwell Ultra B300
100
Spec Wins
Instinct MI300X
65
Detailed Specifications
Blackwell Ultra B300 — Best For
Instinct MI300X — Best For
Who Should Choose Each GPU?
Choose Blackwell Ultra B300 if you…
- ✓Need maximum CUDA/TensorRT/vLLM ecosystem compatibility
- ✓Need more VRAM (288GB vs 192GB) for large model inference
- ✓Prioritize raw FP8 throughput (7,000 vs 2,614 TFLOPS)
- ✓Running Trillion-Parameter Training workloads
- ✓Running AGI Research workloads
- ✓Running Sovereign AI 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 Blackwell Ultra B300 and Instinct MI300X target different priorities. The Blackwell Ultra B300'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 Blackwell Ultra B300's 7,000 FP8 TFLOPS outpaces the Instinct MI300X's 2,614 TFLOPS. Teams already invested in the NVIDIA/CUDA ecosystem will have less friction with the Blackwell Ultra B300, while teams open to ROCM can benefit from the Instinct MI300X's advantages. Use our TCO Calculator to model the full 3-year cost difference for your specific utilization and power costs.
Blackwell Ultra B300 vs Instinct MI300X: Common Questions
Which is faster, Blackwell Ultra B300 or Instinct MI300X?+
In FP8 throughput, the Blackwell Ultra B300 leads with 7,000 TFLOPS vs 2,614 TFLOPS. For LLM inference, memory capacity and bandwidth often matter more than raw TFLOPS — the Blackwell Ultra B300 has more VRAM (288GB).
Is Blackwell Ultra B300 or Instinct MI300X better for LLM training?+
For LLM training at scale, the Blackwell Ultra B300 has higher raw throughput. However, the choice also depends on your software stack: Blackwell Ultra B300 offers CUDA compatibility with the widest framework support (PyTorch, JAX, TensorRT).
What is the price difference between Blackwell Ultra B300 and Instinct MI300X?+
The Blackwell Ultra B300 is estimated at $40,000 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, Blackwell Ultra B300 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: Blackwell Ultra B300 = 5.0 TFLOPS/W vs Instinct MI300X = 3.5 TFLOPS/W.