The Evolution of LLM Architectures in 2025: Balancing Efficiency and Innovation Seven years after the original GPT architecture emerged, core Transformer designs remain remarkably resilient. As we peel back the layers of datasets and training techniques, what fundamental innovations are truly advancing large language models? Key Architectural Innovations at a Glance Key Innovation Leading Models Primary Advantage Technical Approach MLA Attention DeepSeek-V3/R1 68% KV cache reduction Key-value vector compression Sliding Window Attn. Gemma 3 40% context memory savings Localized attention focus Mixture-of-Experts Llama 4/Qwen3 17-37B active params from 100B+ Dynamic expert routing Positionless Encoding SmolLM3 Better long-text generalization Implicit positioning …