Grok Voice Think Fast 2.0 vs Rime Prism

Rime Prism is more reliable, by 1.2 points. Grok Voice Think Fast 2.0 passed 55 of 82 scenarios on all three runs, and Rime Prism passed 56. A scenario only counts when every run of it passed.

For a voice agent, Rime Prism, since it gets more scenarios right on every run. Rime Prism is ahead on reliability, success rate, data accuracy, calls where the agent went quiet and response time, and Grok Voice Think Fast 2.0 on agent responses and interruption.

Rime Prism, by 5.6 points. Grok Voice Think Fast 2.0 saved everything exactly right on 78.9% of the calls that save data, and Rime Prism on 84.5%. On Booking calls, 97.1% against 92.4%. On Medicare calls, 31.8% against 64.2%. A call counts only when nothing is missing, wrong, extra or saved twice.

No. Rime Prism starts replying 0.28s sooner at the median. Grok Voice Think Fast 2.0 takes 1.62s at the median and 1.94s at p90; Rime Prism takes 1.34s and 1.57s. Both are measured on the call audio, from the caller finishing to the agent starting to reply.

Grok Voice Think Fast 2.0, by 0.01 on a 0 to 5 scale. Grok Voice Think Fast 2.0 scores 4.92 and Rime Prism 4.91 for how well the agent handled being talked over.

Rime Prism, by 4.5 points. The agent went quiet for 10 seconds or more on 4.5% of Grok Voice Think Fast 2.0 calls and 0.0% of Rime Prism calls.

There is no verified per-minute rate for Rime Prism, so cost cannot be compared yet.

Cekura ran both as the whole agent in the same open-source Pipecat pipeline, with the same prompt, tools and connection. A simulated caller worked through all 82 scenarios on live calls, three times each, 3,690 calls across the benchmark. A call passes only when the agent said the right things and saved the right data.