The pin-this-on-your-wall table
Below is the practical comparison table for 2026 production decisions. Print it, pin it next to your screen, and consult it before making any architecture commitment.
| Architecture | Core idea | Main advantage | Main weakness | Best use case | Status (2026) |
|---|---|---|---|---|---|
| Transformer | Full pairwise attention | Best recall, most mature ecosystem | O(n²) cost, KV-cache growth | General NLP under 32K, frontier reasoning | Use Now |
| Efficient Transformer (FA3 + GQA + sliding window) | Standard attention with engineering wins | Pragmatic, fully ecosystem-compatible | Still fundamentally quadratic above the window | Up to 64K tokens, recall important | Use Now |
| Mamba / SSM | Selective state-space compression | Linear time, O(1) inference memory | Weak recall, narrow LR window | Throughput- or memory-bound long context | Watch Closely |
| RWKV | RNN-Transformer dual form | Constant per-token cost, 1.5B-device proven | Smaller ecosystem, recall limit ~28K | On-device, streaming, edge | Watch Closely |
| RetNet | Exponential decay retention | Three computation modes | Data-independent decay limits expressiveness | Research foundation, conceptual influence | Research |
| Hyena | Implicit long convolutions | 100× faster than attention at 64K+ | Weak recall, niche language quality | Genomics, byte-level, very long sequences | Watch (domain-specific) |
| Hybrid SSM-Attention | SSM majority + sparse attention layers | Best quality–efficiency balance | Architectural complexity to design from scratch | Long-context production (32K–1M) | Use Now |
| Linear Attention (Kimi Linear, MHLA) | Smarter linear-attention with state structure | Drop-in for Transformer, large speedups | Newer, less battle-tested | Long-context summarization, streaming | Watch Closely |
How to read this table
Use Now means: production-ready, mature tooling, defensible to your team and your CFO. Watch Closely means: real production deployments exist, the architecture is solidifying, you should be able to evaluate it in 2026 if your workload pushes you there. Research means: conceptually important and worth understanding, but no production case in 2026 where you'd pick it over a competing alternative.