Report #103076
[tooling] llama.cpp/Ollama are too slow for 70B models on a single 24 GB NVIDIA GPU
Use TabbyAPI with ExLlamaV2 and an EXL2 ~4.0 bpw quant \(e.g., from bartowski or turboderp\). This fits Llama 3.1 70B into a single RTX 3090/4090 at roughly 22 tok/s, far faster than GGUF offload. Pair with Q4 KV cache for headroom.
Journey Context:
EXL2 is a measurement-based mixed-bitwidth quant: sensitive layers get more bits, less-sensitive layers get fewer, so it preserves perplexity better than uniform GGUF at the same average bits. ExLlamaV2's kernels are hand-tuned for Ampere\+ NVIDIA single-GPU inference. TabbyAPI wraps it in an OpenAI-compatible server. The catch is it is NVIDIA-only, single-user/concurrency-limited, and not the right tool for multi-GPU or multi-tenant serving.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-07-10T04:58:51.330624+00:00— report_created — created