RTX PRO 6000 Blackwell vs Instinct MI325X
NVIDIA RTX PRO 6000 Blackwell (Blackwell, 96 GB) against AMD Instinct MI325X (CDNA 3, 256 GB): memory, compute, power and rental price, compared for LLM inference and training.
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Side-by-Side Specifications
| Spec | RTX PRO 6000 Blackwell | Instinct MI325X |
|---|---|---|
| Architecture | Blackwell | CDNA 3 |
| Memory | 96 GB GDDR7 | 256 GB HBM3e |
| Memory bandwidth | 1,792 GB/s | 6,000 GB/s |
| FP16 tensor compute | 1,000 TFLOPS | 2,615 TFLOPS |
| INT8 tensor compute | 2,000 TOPS | 5,230 TOPS |
| Interconnect | PCIe 5.0 · 128 GB/s | Infinity Fabric 3 · 896 GB/s |
| TDP | 600 W | 1000 W |
| Est. on-demand price | ~$5.00/h | ~$8.00/h |
| FP16 TFLOPS per $/h | 200 | 327 |
Highlighted values indicate the stronger spec. Hourly rates are indicative on-demand estimates.
Verdict
Raw performance: The Instinct MI325X leads on FP16 tensor compute (2.6x advantage), which translates directly into higher token throughput for inference and shorter training steps.
Memory: With 256 GB per card, the Instinct MI325X fits larger models on fewer GPUs — fewer cards means less inter-GPU communication and simpler deployments.
Value: At current on-demand rates, the Instinct MI325X delivers more compute per dollar (327 vs 200 FP16 TFLOPS per $/h). If your model fits in its VRAM budget, it is usually the more economical choice.
GPUs Needed for Popular LLMs
Cards required to serve each model at 8-bit quantization (with 20% overhead for activations and KV cache).
| Model | VRAM (8-bit) | RTX PRO 6000 Blackwell | Instinct MI325X |
|---|---|---|---|
| GPT-5.6 Sol | 2682 GB | 28x | 11x |
| DeepSeek V4 Pro (671B) | 750 GB | 8x | 3x |
| Muse Spark 1.1 | 335 GB | 4x | 2x |
| Claude 5 Sonnet (175B) | 196 GB | 3x | 1x |
| Nova Premier (80B) | 89 GB | 1x | 1x |
| Nova Core (34B) | 38 GB | 1x | 1x |
| Nova Lite (12B) | 13 GB | 1x | 1x |
| Phi 3.5 (3.8B) | 4 GB | 1x | 1x |
Frequently Asked Questions
Which is better for LLM inference: RTX PRO 6000 Blackwell or Instinct MI325X?
The Instinct MI325X delivers more raw FP16 compute (2,615 TFLOPS) and the Instinct MI325X offers the most memory per card (256 GB). For cost-efficiency, the Instinct MI325X currently gives more FP16 TFLOPS per dollar of on-demand rental (327 vs 200 TFLOPS per $/h).
How much more memory does the Instinct MI325X have?
The RTX PRO 6000 Blackwell has 96 GB of GDDR7 versus 256 GB of HBM3e for the Instinct MI325X — a ratio of 2.67x in favor of the Instinct MI325X. More VRAM per card means fewer GPUs to fit a given model.
Is the RTX PRO 6000 Blackwell or the Instinct MI325X cheaper to rent?
Estimated on-demand rates are ~$5.00/h for the RTX PRO 6000 Blackwell and ~$8.00/h for the Instinct MI325X. Raw hourly price is only part of the story: normalize by throughput (TFLOPS per $/h) and by how many cards you need for your model's VRAM.
How do the RTX PRO 6000 Blackwell and Instinct MI325X compare on power?
The RTX PRO 6000 Blackwell has a TDP of 600W versus 1000W for the Instinct MI325X. FP16 compute per watt: 1.7 vs 2.6 TFLOPS/W.
Deploy on a GPU cloud
Rent the RTX PRO 6000 Blackwell or Instinct MI325X by the hour instead of buying hardware.
