GPT Realtime 2.1 is ahead of Deepslate Opal on all eight metrics.
Last updated Methodology by Dileep Chagam
GPT Realtime 2.1 is the better pick over Deepslate Opal on every measure that separates them: reliability across repeated calls (22.0 points higher), calls that pass every check (19.1 points higher), getting the agent's replies right (3.3 points higher), saving the caller's data correctly (19.4 points higher), fewer stalled calls (2.0 points lower), handling interruptions (0.02 higher), fast replies (0.34s sooner) and lower cost ($0.027 cheaper).
Scenarios that passed on all three runs.
GPT Realtime 2.1, 22.0 points higher
Calls that passed every check.
GPT Realtime 2.1, 19.1 points higher
Calls where the agent's replies reached the expected outcome.
GPT Realtime 2.1, 3.3 points higher
Calls where everything the agent saved matched exactly.
GPT Realtime 2.1, 19.4 points higher
Calls where the agent went silent for 10 seconds or more.
GPT Realtime 2.1, 2.0 points lower
How well it handled being talked over, 0 to 5.
GPT Realtime 2.1, 0.02 higher
Median time to start replying after the caller finishes.
GPT Realtime 2.1, 0.34s sooner
One minute of call at the vendor's published rates.
GPT Realtime 2.1, $0.027 cheaper
The small figure is the place among ranked models. The cascade is not ranked.
GPT Realtime 2.1 1.94s, Deepslate Opal 2.27s at the median.
GPT Realtime 2.1 is more reliable, by 22.0 points. Deepslate Opal passed 47 of 82 scenarios on all three runs, and GPT Realtime 2.1 passed 65. A scenario only counts when every run of it passed.
For a phone agent, GPT Realtime 2.1, since it gets more scenarios right on every run. GPT Realtime 2.1 is ahead of Deepslate Opal on all eight metrics.
GPT Realtime 2.1, by 19.4 points. Deepslate Opal saved everything exactly right on 72.6% of the calls that save data, and GPT Realtime 2.1 on 92.0%. On Appointments, 85.4% against 95.9%. On Medicare, 39.4% against 81.8%. A call counts only when nothing is missing, wrong, extra or saved twice.
No. GPT Realtime 2.1 starts replying 0.34s sooner at the median. Deepslate Opal takes 2.27s at the median and 2.83s at p90; GPT Realtime 2.1 takes 1.94s and 2.46s. Both are measured on the call audio, from the caller finishing to the agent starting to reply.
GPT Realtime 2.1, by 0.02 on a 0 to 5 scale. Deepslate Opal scores 4.96 and GPT Realtime 2.1 4.98 for how well the agent handled being talked over.
GPT Realtime 2.1, by 2.0 points. The agent went silent for 10 seconds or more on 5.3% of Deepslate Opal calls and 3.3% of GPT Realtime 2.1 calls.
GPT Realtime 2.1 is $0.027 cheaper a minute. Deepslate Opal costs $0.112 a minute of call and GPT Realtime 2.1 $0.085, at each vendor's published rates.
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, 2,952 calls across the benchmark. A call passes only when the agent said the right things and saved the right data.
