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Gemini 4 Argon vs GPT-OSS 120B (Workers AI)

Reading a 26.2K-token pull request costs $0.0524 on Gemini 4 Argon, 5.7× the $0.0092 it costs on GPT-OSS 120B (Workers AI). Gemini 4 Argon is a mid-range model and GPT-OSS 120B (Workers AI) a economy one. In the benchmark Gemini 4 Argon caught 42 percentage points more of the known defects than GPT-OSS 120B (Workers AI) (95% interval +29 pts to +55 pts, a − b).

Side by side

Gemini 4 Argon and GPT-OSS 120B (Workers AI) side by side
FigureGemini 4 ArgonGPT-OSS 120B (Workers AI)
Price tierMid-rangeEconomy
Bugs caughtshare of known bugs82% (better)40%
False alarmsper clean PR1.1 (better)2.5
Cost per reviewmeasured$0.0527$0.0075 (better)
Cost per bug caught$0.0706$0.0189 (better)
Exact linecatches on the expected lines78% (better)49%
Review timemean99s55s (better)
Typical review calllist price$0.0766$0.011 (better)
Input / 1M tokens$2.00$0.35 (better)
Output / 1M tokens$10.00$0.75 (better)
Context window1M128K

Head to head

The known bugs both were scored on, by who caught each in at least one run.

Of 42 known bugs both were scored on: Both 27Only Gemini 4 Argon 9Only GPT-OSS 120B (Workers AI) 2Neither 4

By language

Share of known bugs each model caught, by language
ModelAllTypeScript6 bugsGo4 bugsJava4 bugsRust4 bugsC#3 bugsJavaScript3 bugsKotlin3 bugsPHP3 bugsPython3 bugsRuby3 bugsSwift3 bugsC++2 bugsC1 bug
Gemini 4 Argon82%83%50%83%75%89%67%100%100%83%100%100%100%0%
GPT-OSS 120B (Workers AI)40%42%13%46%71%41%11%44%33%78%33%44%33%0%

Where they differ

Of the 42 known bugs both were scored on, both caught 27 and neither caught 4. Gemini 4 Argon caught 9 bugs that GPT-OSS 120B (Workers AI) missed: 2 in Go, 1 in C++, 1 in C#, 1 in JavaScript, 1 in Kotlin, 1 in PHP, 1 in Ruby and 1 in Swift. GPT-OSS 120B (Workers AI) caught 2 bugs that Gemini 4 Argon missed: 2 in Go.

On pull requests with no known bug, Gemini 4 Argon raised 1.1 false alarms per review and GPT-OSS 120B (Workers AI) 2.5. A measured review cost $0.0527 on Gemini 4 Argon, 7.0× the cost of $0.0075 on GPT-OSS 120B (Workers AI).

Each known bug, and how often each model caught it
Pull requestLanguage · kindGemini 4 ArgonGPT-OSS 120B (Workers AI)
dotnet/orleansfix(serialization): cap codec allocationsC# · Logic1/10/3
ggml-org/llama.cpprpc : cache and reuse compute graphsC++ · Security1/10/3
go-chi/chifeat: middleware.ClientIP, a replacement for middleware.RealIPGo · Security1/10/3
groue/GRDB.swiftDatabaseQueue and DatabaseSnapshot reads can access task localsSwift · Concurrency1/10/3
kotest/kotestFix DataClassEq comparatorKotlin · Logic1/10/3
rails/railsReimplement Action Cable redis adapter with redis-clientRuby · Logic1/10/3
sindresorhus/p-throttleAdd `weight` optionJavaScript · Logic1/10/3
symfony/symfony[Security] Allow multiple OIDC discovery endpointsPHP · Security1/10/3
traefik/traefikAdd the option to define custom cipher suites for backend serversTransportGo · API misuse1/10/6
go-gitea/giteaperf(gitdiff): optimize inline diff highlighting using cacheGo · Error handling0/11/3
golang/gocrypto/tls: add LocalCertificate to ConnectionStateGo · Logic0/11/6

Defects caught over all runs: a PR reviewed three times with one known bug shows 3/3 when it was caught every time.

Every bug each was scored on: Gemini 4 Argon and GPT-OSS 120B (Workers AI).