NVIDIA DGX Spark vs NVIDIA RTX Pro 4000 Blackwell SFF for local LLMs
86 reports on the NVIDIA DGX Spark and 3 on the NVIDIA RTX Pro 4000 Blackwell SFF
Which is faster for local LLMs?
Nobody has reported the same model at the same quant on both cards yet, so there's no measured head-to-head. Memory bandwidth, which caps how fast a card can write, is 1.6x higher on the NVIDIA RTX Pro 4000 Blackwell SFF (273 GB/s on the NVIDIA DGX Spark, 432 on the NVIDIA RTX Pro 4000 Blackwell SFF). The estimates below compare them on the models people run most.
- Memory
- 128GB unified
- Memory bandwidth
- 273 GB/s
- FP16 compute
- 125 TFLOPS
- Reports
- 86
- Memory
- 24GB
- Memory bandwidth
- 432 GB/s
- FP16 compute
- 96.3 TFLOPS
- Reports
- 3
Estimated by the calculator
The quant the calculator recommends for each card and its estimated speed at a 32,768-token context with 32 GB of system RAM, from memory bandwidth and the model's shape.
| Model | NVIDIA DGX Spark | NVIDIA RTX Pro 4000 Blackwell SFF |
|---|---|---|
| Qwen3.8 27B | 4.0 t/sFP16 | 15.6 t/sQ4_K_M |
| Qwen3.8 125B · 6B active | 14.4 t/sQ6_K | 17.6 t/sQ2_K, experts in RAM |
| Qwen3.6 35B · 3B active | 14.5 t/sFP16 | 55.4 t/sQ4_K_S |
| DeepSeek V4 Flash 284B · 13B active | 38.3 t/sQ2_K | doesn't fit at these settings |
| Qwen3.6 27B | 4.0 t/sFP16 | 15.6 t/sQ4_K_M |
| Gemma 4 26B · 4B active | 10.8 t/sFP16 | 35.3 t/sQ5_K_S |
Change the context, RAM or model in the calculator: NVIDIA DGX Spark · NVIDIA RTX Pro 4000 Blackwell SFF
Every report on each card, with its source: NVIDIA DGX Spark · NVIDIA RTX Pro 4000 Blackwell SFF