Grok Voice Think Fast 2.0xAI
Wins 10 of 11- Reliability (Pass³)
- 28.6%
- Latency P50
- 1.44s
- Cost per Minute (USD)
- $0.080
Grok Voice Think Fast 2.0 vs GPT Realtime 2.1 Mini
GPT Realtime 2.1 MiniOpenAI
Wins 1 of 11- Reliability (Pass³)
- 14.3%
- Latency P50
- 2.40s
- Cost per Minute (USD)
- $0.020
Grok Voice Think Fast 2.0 is ahead on ELO rating, hearing score, turn taking score, speaking score, task handling score, reliability, calls handled well, calls fully resolved, calls where the agent went quiet and median latency, and GPT Realtime 2.1 Mini on cost.
Last updated Methodology by Dileep Chagam
Who is better at what
Grok Voice Think Fast 2.0GPT Realtime 2.1 Mini
- ELO Rating1030921
- Hearing6654
- Turn Taking7874
- Speaking8271
- Task Handling7065
- Reliability (Pass³)28.6%14.3%
- Pass Rate (score ≥ 80)51.9%39.5%
- Task Completion Rate22.9%13.8%
- Dead-Air Rate (≥ 10 s)8.6%9.0%
- Latency P501.44s2.40s
- Cost per Minute (USD)$0.080$0.020
Results by call
Right every time, on booking and Healthcare calls
Banking callsHealthcare calls
- Grok Voice Think Fast 2.0
- Banking calls
- 22.9%
- Healthcare calls
- 34.3%
- Gap
- 11.4 points
23%34%Grok Voice Think Fast 2.0 - GPT Realtime 2.1 Mini
- Banking calls
- 8.6%
- Healthcare calls
- 20.0%
- Gap
- 11.4 points
9%20%GPT Realtime 2.1 Mini
Related Comparisons
Each model on its own: Grok Voice Think Fast 2.0 and GPT Realtime 2.1 Mini
Grok Voice Think Fast 2.0 vs GPT Realtime 2.1 Mini FAQ
Is Grok Voice Think Fast 2.0 or GPT Realtime 2.1 Mini more reliable?
Grok Voice Think Fast 2.0 is more reliable, by 14.3 points. Grok Voice Think Fast 2.0 handled 20 of 70 real callers well on all three runs, and GPT Realtime 2.1 Mini 10. A caller only counts when every run of the call scored 80 or more.
Grok Voice Think Fast 2.0 is more reliable, by 14.3 points. Grok Voice Think Fast 2.0 handled 20 of 70 real callers well on all three runs, and GPT Realtime 2.1 Mini 10. A caller only counts when every run of the call scored 80 or more.
For a voice agent, Grok Voice Think Fast 2.0, since it handles more real callers well on every run. Grok Voice Think Fast 2.0 is ahead on ELO rating, hearing score, turn taking score, speaking score, task handling score, reliability, calls handled well, calls fully resolved, calls where the agent went quiet and median latency, and GPT Realtime 2.1 Mini on cost.
Grok Voice Think Fast 2.0, by 9.0 points higher. Grok Voice Think Fast 2.0 fully resolved 22.9% of calls and GPT Realtime 2.1 Mini 13.8%. A call counts only when every step the caller needed was done.
Yes. Grok Voice Think Fast 2.0 starts replying 0.96s sooner at the median. Grok Voice Think Fast 2.0 takes 1.44s at the median and 1.83s at p90; GPT Realtime 2.1 Mini takes 2.40s and 2.88s. Both are measured on the call audio, from the caller finishing to the agent starting to reply.
Grok Voice Think Fast 2.0, by 0.5 points. The agent went quiet for 10 seconds or more on 8.6% of Grok Voice Think Fast 2.0 calls and 9.0% of GPT Realtime 2.1 Mini calls.
GPT Realtime 2.1 Mini is $0.060 cheaper a minute. Grok Voice Think Fast 2.0 costs $0.080 a minute of call and GPT Realtime 2.1 Mini $0.020, at each vendor's published rates.
Cekura ran both as the whole agent with the same prompt, tools and phone connection. Both took the same 70 recorded real human callers on live calls, three times each. Each call is graded on 25 skills across Hearing, Turn Taking, Task Handling and Speaking, and passes at a score of 80 out of 100.
Test your voice agent the same way.
Cekura runs these simulated calls on your agent and scores every one.