This article argues that Ollama’s custom backend runs 30–70% slower than llama.cpp, locked users’ models in a proprietary format, and dropped proper attribution before grudgingly reverting. It also criticizes Ollama Cloud’s reliability and warns that the platform has strayed from its local-first, open-source roots.

• Ollama's custom ggml fork runs 30-70% slower than llama.cpp (e.g., 30 vs 52 tokens/sec on RTX 5090 with Qwen3 Coder 32B), despite reverting to upstream llama.cpp in v0.30.0-rc15
• Ollama locked models into a proprietary hashed-filename registry format between 2024 and early 2026, preventing reuse with other tools
• Ollama Cloud Pro users report up to 95% failure rates, long timeouts, broken tool calling, and unanswered support tickets, undermining its local-first pitch
• Ollama mislabeled distilled DeepSeek-R1 variants as the full 671B model and launched its desktop app without source code despite open-source claims