Hardware · Memory
How much memory does a model need?
Pick an LLM and a context length. We add up the weights at every quantization, the KV cache that grows with context, and runtime overhead, then show the smallest systems and devices that hold it.
Kimi K3.1 Pro (2.8T) at 8K context
| Quantization | Weights | KV cache + overhead | Total | Smallest hardware that holds it |
|---|---|---|---|---|
Q2_K |
1,112 GB | 0.8 GB | 1,113 GB | |
Q3_K_M |
1,362 GB | 0.8 GB | 1,363 GB | |
Q4_K_M |
1,696 GB | 0.8 GB | 1,697 GB | |
Q5_K_M |
1,974 GB | 0.8 GB | 1,975 GB | |
Q6_K |
2,280 GB | 0.8 GB | 2,281 GB | |
Q8_0 |
2,947 GB | 0.8 GB | 2,948 GB | |
F16 |
5,560 GB | 0.8 GB | 5,561 GB |
The rule of thumb
1 · WeightsParameters × bytes eachA 70B model at 4 bits per weight is about 70 × 0.6 ≈ 42 GB. Lower quantization shrinks it and costs some quality.
2 · KV cacheGrows with contextEvery token you keep in context stores keys and values for each layer. Doubling context doubles this part, so long documents cost real memory.
3 · OverheadLeave headroomThe runtime, the operating system and other apps need memory too. Aim for a total at least 10% under the memory your GPU or device can give a model.
Estimates come from published hardware specs and our open formulas, not from running the model on your machine. Real speed varies with runtime, drivers and settings. Numbers marked “Measured” come from a linked benchmark.