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Blog/October 2026·5 min

Benchmarking vega against a hosted decision model, honestly

3,841 decisions per system against the live endpoint, same rows, one run. Where the hosted model wins, where vega wins, and why we publish the harness either way.


Most model comparisons on the internet share a flaw: the numbers for the two systems come from different runs, different samples, different prompts. When we put vega against Jev, the hosted decision model in this category, we wanted a comparison that survives hostile reading. So: 3,841 decisions per system, the same rows, one run, vega on local GPUs and Jev over its live endpoint, with the harness and the raw JSON published next to the result.

What the run found

vega 4B · accuracy, public menu0.717
Jev0.836
vega 4B · ECE, DecisionBench0.098
Jev0.122
vega 4B · KL to soft gold0.854
Jev6.099
vega 4B · coverage1.000
Jev0.997
Lower is better for ECE and KL. Same 3,841 rows per system, one run.

Jev wins raw accuracy on the public menu, 0.836 against 0.717, and we print that number as large as the ones we win. vega answers every row where Jev abstains on a few, and on the probability side the gap runs the other way: expected calibration error of 0.098 against 0.122, and KL divergence to the soft gold labels of 0.854 against 6.099. A seven times smaller KL means that when the right answer deserves 60% confidence, vega says something near 60%, while the hosted model says something near certain.

Calibration is not a consolation prize. A decision model's output is consumed by an if statement. The branch that matters is the one where you trust the probability enough to act without a human, and that branch is exactly where miscalibration costs money.

Latency, measured in the same breath

laya 421M33 ms
vega 0.8B74 ms
vega 4B106 ms
Jev (hosted)162 ms
Median per decision. laya on a T4 with one question; vega and Jev in one run on the same rows.

The hosted number includes the network, because that is what a hosted model costs you in production. The local numbers include everything after the request reaches the process.

The rules we benchmark by

Full tables and raw output: vega results and laya benchmarks.


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