Google reportedly tests Gemini 4 checkpoint Carbon, said to match Opus 5.5
Employees are reportedly testing a newer Gemini 4 version codenamed Carbon that is comparable to Opus 5.5, while earlier Argon versions were compared to Opus 5.

google got opus 5.5 level model reportedly employees are testing newer gemini 4 version called carbon and it's comparable to opus 5.5 earlier argon versions were compared to opus 5 but looks like team been cooking with newer checkpoint > argon is the gemini 4 pro model > barium-b is the internal model name chosen to launch as argon > carbon on other hand could be argon update or new gemini 4 model if true then google is about to make banger comeback with these models just hoping they release models soon instead of delaying like gemini 3.5 pro
This post quotes another post: “Rumor points to Gemini 4 family launch next week, including Pro, Flash and Argon”