A 63-hour autonomous Riemann hypothesis run on one 3090 burned 50M+ tokens and never hallucinated an answer.

An r/LocalLLaMA user let Qwen3.8 27B at 4-bit with a 100K window run autonomously for 63 hours attempting the Riemann hypothesis. It didn't solve it, which was never the point. The reported result is that across 63 hours it never fabricated a proof, repeatedly caught and corrected its own errors, and kept generating new attack strategies rather than looping. As a long-horizon durability datapoint on consumer hardware that's more interesting than the math, and it's a cheap experiment to replicate with your own unfalsifiable-but-checkable task.