CDNA 4
AMD Instinct MI355X
wins
4
The AMD Instinct MI355X is AMD's CDNA 4 flagship.
Ampere
NVIDIA RTX A6000
wins
1
The RTX A6000 is NVIDIA's Ampere professional workstation GPU with 48GB GDDR6 and NVLink support.
Performance comparison
Visual bars — winner highlighted
AMD Instinct MI355X
Metric
NVIDIA RTX A6000
FP16 TFLOPS
Bandwidth
VRAM
TDP (lower=better)
TFLOPS/watt
GB/s per watt
Full specification table
| Spec | AMD Instinct MI355X | NVIDIA RTX A6000 |
|---|---|---|
| Architecture | CDNA 4 | Ampere |
| VRAM | 288 GB HBM3e | 48 GB GDDR6 |
| VRAM type | HBM3e | GDDR6 |
| Memory bandwidth | 8,000 GB/s | 768 GB/s |
| FP16 TFLOPS | 2,615 TFLOPS | 154 TFLOPS |
| TDP | 750 W | 300 W |
| TFLOPS/watt | 3.49 T/W | 0.51 T/W |
| GB/s per watt | 10.67 GB/s/W | 2.56 GB/s/W |
| NVLink | No | Yes |
| Release year | 2025 | 2020 |
Live cloud pricing
On-demand pricing across providers — updated in real time
Power efficiency analysis
TFLOPS/watt and GB/s/watt — critical for data center TCO
AMD Instinct MI355X
NVIDIA RTX A6000
TFLOPS/watt measures compute efficiency — how much AI throughput you get per watt of power consumed. For data centers with PUE of 1.2–1.5, a 10% improvement in TFLOPS/watt translates directly to lower electricity costs and cooling requirements. GB/s/watt measures memory bandwidth efficiency, which is the binding constraint for memory-bound LLM inference workloads.
When to choose each GPU
Choose AMD Instinct MI355X for:
- Large LLM inference
- Agent workloads
- Memory-bound AI
Weaknesses / Limitations
- ROCm ecosystem less mature than CUDA — some frameworks require porting
- Very limited cloud availability compared to NVIDIA equivalents
- 750W TDP — high power draw comparable to H100 SXM
Choose NVIDIA RTX A6000 for:
- Professional workstation AI
- Large model inference
- Rendering
Weaknesses / Limitations
- Older Ampere architecture — lower TFLOPS than Ada equivalents at same VRAM
- GDDR6 bandwidth (768 GB/s) lower than HBM-based GPUs
- Superseded by RTX 6000 Ada and RTX PRO 6000 on new deployments
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