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LLM VRAM Calculator (all models)

Can You Run Kimi K3 (2.8T MoE)? VRAM Requirements

Kimi K3 (2.8T MoE) has 2.8T total parameters (MoE, 48B active per token). Running it at MXFP4 with 16K context takes roughly 1.46 TB of memory (1.35 TB weights + 1.4 GB KV cache + runtime overhead). The minimum viable hardware is about 9× B200 192GB. All numbers are planning estimates, verified 2026-07-27.

⚠ Some architecture details of this model are estimated — treat results as ballpark figures.

VRAM by quantization (16K context)

QuantizationWeightsTotal neededMinimum hardware
FP16 / BF165.09 TB5.50 TB32× B200 192GB
FP82.55 TB2.75 TB16× B200 192GB
Q8_0 (GGUF)2.70 TB2.92 TB17× B200 192GB
Q6_K (GGUF)2.09 TB2.26 TB14× B200 192GB
Q5_K_M (GGUF)1.81 TB1.95 TB12× B200 192GB
MXFP4recommended1.35 TB1.46 TB9× B200 192GB
Q4_K_M (GGUF)1.55 TB1.68 TB10× B200 192GB
Q3_K_M (GGUF)1.20 TB1.29 TB8× B200 192GB
Q2_K (GGUF)913 GB987 GB6× B200 192GB

How context length changes memory (MXFP4)

ContextKV cacheTotal needed
4K0.3 GB1.46 TB
16K1.4 GB1.46 TB
64K5.5 GB1.46 TB
128K11.0 GB1.47 TB
256K22.0 GB1.48 TB
1M83.8 GB1.54 TB

KV cache grows linearly with context; FP8 KV cache halves it again (try it in the calculator below).

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LLM VRAM Calculator — Can I Run It?

Estimate how much GPU memory (VRAM) you need to run open-weight LLMs like Kimi K3, DeepSeek R1, Qwen3, or Llama locally. Pick a model, quantization, and context length — the calculator adds up weights, KV cache, and runtime overhead, then shows which GPUs or Macs can fit it. Runs entirely in your browser: no upload, no signup.

2.8T total params · 48B active (MoE) · max 1M context · specs partially estimated

Native format of Kimi K3 / gpt-oss · ~0.53 bytes/param

Estimated memory needed

1.47 TB

Model weights1.35 TB
KV cache (131,072 tokens)11.0 GB
Runtime overhead111 GB

Architecture details for this model are estimated — treat results as a ballpark.

Will it fit?

RTX 3060 12GB137× needed
RTX 4060 Ti 16GB103× needed
RTX 3090 / 4090 24GB69× needed
RTX 5090 32GB52× needed
A100 40GB41× needed
A100 / H100 80GB21× needed
H200 141GB12× needed
AMD MI300X 192GB9× needed
B200 192GB9× needed
Mac 36GB unified✗ too big
Mac 64GB unified✗ too big
Mac 128GB unified✗ too big
Mac M3 Ultra 512GB✗ too big

Assumes ~92% of device memory is usable. Multi-GPU counts are for tensor/pipeline parallel serving (vLLM, SGLang); Apple Silicon uses unified memory via llama.cpp or MLX.

FAQ

How much VRAM does Kimi K3 (2.8T MoE) need?

About 1.46 TB at the recommended MXFP4 quantization with 16K context: 1.35 TB for weights, 1.4 GB for KV cache, plus runtime overhead. Longer context grows the KV cache.

What is the minimum hardware for Kimi K3 (2.8T MoE)?

Roughly 9× B200 192GB, assuming 92% of device memory is usable. Lower-end setups can try more aggressive quantization (Q3/Q2) at a noticeable quality cost.

Can I run Kimi K3 (2.8T MoE) on a Mac?

Not realistically. Even at MXFP4 it needs about 1.46 TB, which exceeds the largest Mac M3 Ultra 512GB. Use a multi-GPU server or an API instead.

Which quantization should I use for Kimi K3 (2.8T MoE)?

MXFP4 is the model's native/recommended format — Native format of Kimi K3 / gpt-oss. Pick Q4_K_M for a smaller footprint or FP8 / Q8_0 for near-lossless quality.

VRAM requirements for other models