Can Llama 3.1 8B run on iPhone 15?
NO — Won't fit
Grade F · 12/100 · formula estimate
What this means
None of the versions we checked fit safely on this phone. The checked version needs about 6.3 GB, while we estimate that the model can use about 3.9 GB.
Try a smaller model, or use this model on a device with more memory.
This result is calculated from the phone and model specifications. It has not been measured on this exact phone and setup.
−2.4GB short
memory that doesn't exist here
6.3GB
needed at Q4_K_M
Q4_K_M
quant checked
F
grade · 12/100
needs 6.3 GBusable 3.9 GB · short 2.4 GB
Apple A16 Bionic6 GB RAMMetal
Three ways forward
1
Try a smaller quant
No quant of Llama 3.1 8B fits this phone — even the smallest is too big. Options 2 and 3 are your real choices.
3
Run it in the cloud
The full Llama 3.1 8B, no download, at data-center speed — pay per token.
provider recommendations coming later
Where the memory goes
| Component | Detail | GB |
|---|---|---|
| Model weights | Q4_K_M GGUF (4.9 GB) + mmap overhead | 5.1 |
| KV cache | 4K context window | 0.6 |
| Runtime | llama.cpp + app overhead | 0.6 |
| Total needed | at Q4_K_M, 4K context | 6.3 |
| Usable on iPhone 15 | 6 GB RAM − iOS reserve (jetsam limit) | 3.9 |
| Headroom | missing — this memory doesn't exist | −2.4 |
Pick your quant
| Quant | Download | Verdict | Speed |
|---|---|---|---|
| Q2_K | 3.2 GB | ✕ Won't fit | won't fit |
| Q3_K_M | 4 GB | ✕ Won't fit | won't fit |
| IQ4_XS | 4.4 GB | ✕ Won't fit | won't fit |
| Q4_0 | 4.7 GB | ✕ Won't fit | won't fit |
| Q4_K_S | 4.7 GB | ✕ Won't fit | won't fit |
| Q4_K_M | 4.9 GB | ✕ Won't fit | won't fit |
| Q5_K_M | 5.7 GB | ✕ Won't fit | won't fit |
| Q6_K | 6.6 GB | ✕ Won't fit | won't fit |
| Q8_0 | 8.5 GB | ✕ Won't fit | won't fit |
Related checks
MORE ON IPHONE 15
LLAMA 3.1 8B ON OTHER PHONES