Solar Pro 4 hits 42 on AI index

Korean AI outfit Upstage just shipped its flagship reasoning model, Solar Pro 4 — and the benchmark numbers are a serious glow-up. Artificial Analysis now puts the model's intelligence index at 42, up from 14 on Solar Pro 3. The jump mostly comes from agentic and long-context performance.

Terminal-Bench v2.1 climbed from 12% to 57%, and long-context reasoning went from 31 to 71. The GDPval-AA v2 leaderboard score also rocketed from 498 Elo to 1277, clearing the 1000 human baseline. Consider Solar Pro 4 Korea's best shot yet at the global frontier.

But across the border, DeepSeek V4 Flash 0731 is still having its way. On the same Artificial Analysis index, DeepSeek grabs 52 — a full 10 points higher. And it's roughly twice as fast, spitting out about 122 tokens per second to Solar's 65.

Then there's price. Solar Pro 4 charges $0.30 per million input tokens and $1.20 per million output tokens. DeepSeek asks $0.14 and $0.28, respectively. Solar's output price is more than four times steeper.

So by this benchmark and API value, Korea's AI pride still hasn't caught DeepSeek.