Why Grouped Query Attention (GQA) Outperforms Multi-head Attention

What if one architecture tweak made Llama 3 5× faster with 99.8% of the quality? In this deep dive, we break down Grouped Query Attention (GQA)—why it slashes KV-cache memory, speeds up inference, and avoids the instability of Multi-Query Attention. We compare MHA vs MQA vs GQA, show how GQA-8 became the modern default, and share intuition, pitfalls, and next steps (FlashAttention, KV-cache quantization, MHLA). Grouped Query Attention GQA GQA-8 Multi-Head Attention MHA Multi-Query Attention MQA attention mechanisms KV cache KV cache memory KV cache optimization inference latency inference spe…