Can I Run Qwen 2.5 Family on 8 GB system RAM?
Superseded model. Qwen 2.5 Family has been superseded by Qwen 3. This page is kept for reference; the newer family is a better starting point.
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Written by Jakub Rusinowski · Last updated November 12, 2024
Yes, but it is tight
Yes, but it is tight — Qwen 2.5 7B Instruct at Q4_K_M needs about 5.9 GB of the 6.4 GB usable on 8 GB system RAM, leaving only ~0.5 GB before the runtime starts swapping. Expect ~13.5 tok/s (estimated), with room for about 16,384 tokens of context.
Confidence: medium · Recommended quantization: Q4_K_M · Estimated speed: ~13.5 tok/s
8 GB system RAM — what it gives a model
| Usable memory for models | 6.4 GB |
| Memory bandwidth | 90 GB/s |
Qwen 2.5 Family on 8 GB system RAM: memory by quantization
| Quant | Memory needed | Fits 6.4 GB? | Max context | Est. speed | Download |
|---|
| F16 | 16.5 GB | ✗ No | — | — | 15.2 GB |
| Q8_0 | 9.3 GB | ✗ No | — | — | 8.1 GB |
| Q6_K | 7.5 GB | ✗ No | — | — | 6.2 GB |
| Q5_K_M | 6.7 GB | ✗ No | — | — | 5.4 GB |
| Q4_K_M | 5.9 GB | ✓ Yes | 16K | ~13.5 tok/s | 4.6 GB |
| Q3_K_M | 4.5 GB | ✓ Yes | 32K | ~18.5 tok/s | 3.2 GB |
| Q2_K | 3.8 GB | ✓ Yes | 32K | ~23.3 tok/s | 2.5 GB |
Which Qwen 2.5 Family sizes fit
| Variant | Needs at Q4_K_M | Fits? | Est. speed |
|---|
| Qwen 2.5 72B Instruct | 47 GB | ✗ Too large | — |
| Qwen 2.5 Coder 32B | 22.3 GB | ✗ Too large | — |
| Qwen 2.5 14B Instruct | 10.9 GB | ✗ Too large | — |
| Qwen 2.5 7B Instruct | 5.9 GB | ✓ Fits | ~13.5 tok/s |
What to watch out for
- Only ~0.5 GB of headroom at Q4_K_M: a longer context or a second application can push this into swapping.
- 3 larger variants of Qwen 2.5 Family do not fit and would need CPU offload or different hardware.
- These figures assume CPU-only inference. Any discrete GPU, even an 8 GB one, will be several times faster for models that fit in its VRAM.
Recommended setup
llama.cpp (CPU build) or Ollama — both run without a GPU
How these numbers are calculated
- Memory need = quantized weights + KV cache at 8,192 tokens (f16) + 0.8 GB runtime overhead.
- 6.4 GB of the 8 GB is treated as usable for model weights (80% — the rest is the OS and running applications).
- DDR5-5600 dual channel at 89.6 GB/s peak. CPU decode is assumed to sustain 35% of that peak, because CPU inference is not purely bandwidth-bound — it also spends real time in compute and thread synchronisation. This figure is an assumption, not a fitted constant: no CPU measurement is in the calibration set.
- CPU-only inference: no GPU is assumed. A GPU of any size will beat these figures substantially.
- Throughput is a memory-bandwidth roofline estimate, not a measurement. It is labelled "estimated" everywhere it appears.
- KV cache is computed from this model's published attention configuration.
FAQ
Can I run Qwen 2.5 Family on 8 GB system RAM?
Yes, but it is tight — Qwen 2.5 7B Instruct at Q4_K_M needs about 5.9 GB of the 6.4 GB usable on 8 GB system RAM, leaving only ~0.5 GB before the runtime starts swapping. Expect ~13.5 tok/s (estimated), with room for about 16,384 tokens of context.
Which quantization of Qwen 2.5 Family should I use on 8 GB system RAM?
Q4_K_M — it needs about 5.9 GB of the 6.4 GB available, downloads as roughly 4.6 GB, and runs at an estimated 13.5 tokens/sec with up to 16K of context.
What limits Qwen 2.5 Family on 8 GB system RAM?
Nothing binding — the model fits with headroom and generates at a usable speed on this hardware.
Which runtime should I use?
llama.cpp (CPU build) or Ollama — both run without a GPU
Other RAM Capacities
Other Models on 8 GB system RAM
Qwen 2.5 Family on GPUs
What This Model Is Good At
Model & Tools
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