inference/research
verifiedhigh · 0.90updated 2026-10-03

Llama 3.3 70B

dense 70.55B

Fields

id
models/llama-3-3-70b
Family
llama
Vendor
Meta
Release year
2024
Architecture
dense
Params (B)
70.55
Active params (B)
70.55
Hidden size
8,192
Layers
80
KV heads
8
Head dim
128
GQA ratio
8
Max context
131,072
Context scaling
llama3 rope scaling (factor 8 from an 8192 base)
Context scaling method
llama3
Activation
silu
Attention variant
GQA
KV cache (bytes/token)
327,680
FLOPs per active token
141,100,000,000
Open weights
yes
License
Llama 3.3 Community License
notes
PARAMS: 70.55B is the safetensors count. KV: 80 * 8 * 128 * 2 * 2 bytes = 327,680 bytes/token = 320 KiB/token. Compare with the 8B model: 2.5x the KV per token of an 8B at the same context. At 128k that is 40 GiB of KV for a single sequence, which is the practical reason 70B-class GQA serving is context-limited, not weight-limited. 8 kv heads against 64 query heads is the most aggressive GQA ratio in common deployment. SOURCE CAVEAT: unsloth mirror of Meta weights, not first-party. SERVICEABILITY JOIN (added 2026-10-03; the architecture x engine matrix this record was missing, with a citation per cell in docs/13-model-compatibility.md): FAMILY=dense-gqa. REQUIRED KERNEL CLASS: ordinary causal attention plus GEMM/GEMV. This is the baseline every engine in this repo implements, so the join here is a floor rather than a filter: no engine record in data/engines/ states that dense GQA is unsupported. SUPPORTED BY (cited): vLLM LlamaForCausalLM / Qwen2 / Qwen3 / Mistral / Phi3ForCausalLM rows [[mdl2-vllm-supported-models-2026-10]]; TensorRT-LLM LlamaForCausalLM, Qwen2ForCausalLM, Qwen3ForCausalLM, Phi3ForCausalLM rows [[mdl2-trtllm-supported-models]]; SGLang generative table (Llama, Qwen, Mistral families) [[mdl2-sglang-generative-models]]; llama.cpp LLM_ARCH_LLAMA [[pap-arch-llamacpp-arch-registry]]. HARD CONSTRAINTS THAT DO APPLY even to dense GQA, and they are model-shape rather than architecture-class: tensor-parallel size must divide the attention head count or the engine refuses to start [[mgpu-tp-size-must-divide-attention-heads]] (affects vllm and sglang); and a GQA KV cache is the thing paged-attention machinery exists for, so an engine with no paged KV (llama.cpp's slot-based pool [[llama-cpp]], exllamav2 [[exllamav2]]) loses the concurrency lever rather than the ability to run. ONE HARDWARE-DEPENDENT KERNEL GATE THAT IS NOT ABOUT GQA: on RDNA, vLLM's custom paged-attention kernel is gated on head_size == 128 AND block_size == 16, so a dense GQA model with head_dim 256 falls to the Triton 2D fallback and decode falls off a cliff - measured 12.1 tok/s at 518 tokens of context to 4.2 tok/s at 32k, with kernel_paged_attention_2d growing 28.3x [[rdna-triton-paged-attn-decode-cliff]]. Check head_dim before blaming the card. CONTEXT_SCALING_METHOD (llama3): config-derived; the existing free text 'llama3 rope scaling (factor 8 from an 8192 base)' agrees.

Notes

PARAMS: 70.55B is the safetensors count. KV: 80 * 8 * 128 * 2 * 2 bytes = 327,680 bytes/token = 320 KiB/token. Compare with the 8B model: 2.5x the KV per token of an 8B at the same context. At 128k that is 40 GiB of KV for a single sequence, which is the practical reason 70B-class GQA serving is context-limited, not weight-limited. 8 kv heads against 64 query heads is the most aggressive GQA ratio in common deployment. SOURCE CAVEAT: unsloth mirror of Meta weights, not first-party.

SERVICEABILITY JOIN (added 2026-10-03; the architecture x engine matrix this record was missing, with a citation per cell in docs/13-model-compatibility.md): FAMILY=dense-gqa. REQUIRED KERNEL CLASS: ordinary causal attention plus GEMM/GEMV. This is the baseline every engine in this repo implements, so the join here is a floor rather than a filter: no engine record in data/engines/ states that dense GQA is unsupported. SUPPORTED BY (cited): vLLM LlamaForCausalLM / Qwen2 / Qwen3 / Mistral / Phi3ForCausalLM rows [[mdl2-vllm-supported-models-2026-10]]; TensorRT-LLM LlamaForCausalLM, Qwen2ForCausalLM, Qwen3ForCausalLM, Phi3ForCausalLM rows [[mdl2-trtllm-supported-models]]; SGLang generative table (Llama, Qwen, Mistral families) [[mdl2-sglang-generative-models]]; llama.cpp LLM_ARCH_LLAMA [[pap-arch-llamacpp-arch-registry]]. HARD CONSTRAINTS THAT DO APPLY even to dense GQA, and they are model-shape rather than architecture-class: tensor-parallel size must divide the attention head count or the engine refuses to start [[mgpu-tp-size-must-divide-attention-heads]] (affects vllm and sglang); and a GQA KV cache is the thing paged-attention machinery exists for, so an engine with no paged KV (llama.cpp's slot-based pool [[llama-cpp]], exllamav2 [[exllamav2]]) loses the concurrency lever rather than the ability to run. ONE HARDWARE-DEPENDENT KERNEL GATE THAT IS NOT ABOUT GQA: on RDNA, vLLM's custom paged-attention kernel is gated on head_size == 128 AND block_size == 16, so a dense GQA model with head_dim 256 falls to the Triton 2D fallback and decode falls off a cliff - measured 12.1 tok/s at 518 tokens of context to 4.2 tok/s at 32k, with kernel_paged_attention_2d growing 28.3x [[rdna-triton-paged-attn-decode-cliff]]. Check head_dim before blaming the card.

CONTEXT_SCALING_METHOD (llama3): config-derived; the existing free text 'llama3 rope scaling (factor 8 from an 8192 base)' agrees.

Cross-references

This record references no other records — it is a leaf. It is cited by 12.