NVIDIA DGX Spark vs M5 Ultra 512GB for local LLMs
91 reports on the NVIDIA DGX Spark and 1 on the M5 Ultra 512GB
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 4.5x higher on the M5 Ultra 512GB (273 GB/s on the NVIDIA DGX Spark, 1,229 on the M5 Ultra 512GB). The estimates below compare them on the models people run most.
NVIDIA DGX Spark
- Memory
- 128GB unified
- Memory bandwidth
- 273 GB/s
- FP16 compute
- 125 TFLOPS
- Reports
- 91
M5 Ultra 512GB
- Memory
- 512GB unified
- Memory bandwidth
- 1,229 GB/s
- FP16 compute
- not on record
- Reports
- 1
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 | M5 Ultra 512GB |
|---|---|---|
| Qwen3.8 27B | 4.0 t/sFP16 | 14.9 t/sFP16 |
| Qwen3.8 125B · 6B active | 14.4 t/sQ6_K | 25.4 t/sFP16 |
| Qwen3.6 35B · 3B active | 14.5 t/sFP16 | 53.5 t/sFP16 |
| DeepSeek V4 Flash 284B · 13B active | 38.3 t/sQ2_K | 42.1 t/sQ8_0 |
| Qwen3.6 27B | 4.0 t/sFP16 | 14.9 t/sFP16 |
| Gemma 4 26B · 4B active | 10.8 t/sFP16 | 40.1 t/sFP16 |
Change the context, RAM or model in the calculator: NVIDIA DGX Spark · M5 Ultra 512GB
Every report on each card, with its source: NVIDIA DGX Spark · M5 Ultra 512GB