Astra Low vs Sol High vs Terra High credit usage measurement
A developer conducted a test comparing the credit usage of GPT-6 Astra Low, GPT-5.6 Sol High, and GPT-5.6 Terra High on an identical Codex task. The initial test with Astra Low yielded a cost of $2.23. To ensure accuracy and rule out cached token effects, the Astra Low test was re-run, producing the exact same cost of $2.23, confirming consistent measurement for the comparison of these models.
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PublishedOffset at this time: UTC+0Sep 11, 2026, 12:46 UTC
IngestedOffset at this time: UTC+0Sep 12, 2026, 12:01 UTC
- Published
- Sep 11, 2026, 12:46
- Ingested
- Sep 12, 2026, 12:01
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I ran a small test comparing the cost of GPT-6 Astra Low, GPT-5.6 Sol High, and GPT-5.6 Terra High on the exact same Codex task.
I asked all three to export the full conversation history from a medium-sized Codex chat as an .md file, using the least amount of tokens possible. I used the exact same prompt for each model.
I recorded my account balance before and after each task, then calculated the actual cost of each individual run from the difference.
Cost per completed task:
- Astra Low: $2.23
- Sol High: $0.32
- Terra High: $0.42
Yeah... I was very surprised by the difference between Astra and the other models. Astra Low cost roughly 6.9× as much as Sol High for the exact same task.
Obviously, this is a tiny test, so the results may or may not be representative of broader real-world usage. But it is a measurement nonetheless.
Clarification: Same session, same task. Changed the model, "edited" the last message, sent it again.
Edit: To check whether running the same task was using cached tokens and therefore lowering the cost of subsequent tests, I ran the first test (Astra Low) again. The result was exactly the same, down to the last cent: $2.23.