NVIDIA L4 vs M1 Ultra 128GB for local LLMs
3 reports on the NVIDIA L4 and 10 on the M1 Ultra 128GB
Which is faster for local LLMs?
On Qwen3.8 27B at 4-bit, the NVIDIA L4 has 14.6 generation tokens/s (one run); the M1 Ultra 128GB has 25.1 generation tokens/s (one run); prompt processing 153.3 tokens/s (one run). Those are community reports whose engines and settings differ, so the gap is a rough sign, not a controlled measure of the two cards. Memory bandwidth, which caps how fast a card can write, is 2.7x higher on the M1 Ultra 128GB (300 GB/s on the NVIDIA L4, 819 on the M1 Ultra 128GB).
- Memory
- 24GB
- Memory bandwidth
- 300 GB/s
- FP16 compute
- 121 TFLOPS
- Reports
- 3
- Memory
- 128GB unified
- Memory bandwidth
- 819 GB/s
- FP16 compute
- 21 TFLOPS
- Reports
- 10
Measured on both
Generation and prompt processing speeds from plain runs (one device, one request, no speculative decoding, the whole model in the device's memory) of the same model size at the same bit class. Each side shows the engines and reported context behind its median. Context can mean a configured window or prompt depth, so these are community comparisons with differing settings. How to read these
| Model | NVIDIA L4 | M1 Ultra 128GB |
|---|---|---|
| Qwen3.8 27B4-bit | 14.6one runllama.cppcontext not stated | 25.1one runPP 153.3 (one run)engine not statedcontext not stated |
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. Where a model was also measured above, the measurement wins.
| Model | NVIDIA L4 | M1 Ultra 128GB |
|---|---|---|
| Qwen3.8 27B | 10.9 t/sQ4_K_M | 7.5 t/sFP16 |
| Qwen3.8 125B · 6B active | 16.4 t/sQ2_K, experts in RAM | 34.0 t/sQ5_K_S |
| Qwen3.6 35B · 3B active | 38.5 t/sQ4_K_S | 23.5 t/sFP16 |
| DeepSeek V4 Flash 284B · 13B active | doesn't fit at these settings | 53.5 t/sQ2_K |
| Qwen3.6 27B | 10.9 t/sQ4_K_M | 7.5 t/sFP16 |
| Gemma 4 26B · 4B active | 24.5 t/sQ5_K_S | 20.2 t/sFP16 |
| GLM-5.3 320B · 18B active | doesn't fit at these settings | doesn't fit at these settings |
Change the context, RAM or model in the calculator: NVIDIA L4 · M1 Ultra 128GB
Every report on each card, with its source: NVIDIA L4 · M1 Ultra 128GB