GPT-5.6 Terra vs GPT-6 Astra
何時用哪一個
gpt-5.6-terra 與 gpt-6-astra 兩者皆提供相同的 1050000 上下文視窗、128000 最大輸出 token，並支援完全相同的能力與模態。若要大幅節省成本，請選擇 gpt-5.6-terra，因為其 $2.5 的輸入費率與 $15 的輸出費率，遠低於 gpt-6-astra 的 $10 輸入費率與 $50 輸出費率。只有當您的工作負載特別需要其 2026-04 的知識截止時間，而非 gpt-5.6-terra 所提供的 2026-02 截止時間時，才應選擇 gpt-6-astra。
Benchmark 成績
廠商公布: Alibaba (Qwen) Anthropic ByteDance DeepSeek Google MiniMax Moonshot OpenAI Tencent Z.ai
定價
| GPT-5.6 Terra | GPT-6 Astra | Δ | |
|---|---|---|---|
| 輸入 / 1M tokens | $2.5 | $10 | 0.25× |
| 輸出 / 1M tokens | $15 | $50 | 0.3× |
| 快取讀取 / 1M tokens | $0.25 | $1 | 0.25× |
| 快取寫入 | 不額外計費 | 不額外計費 | - |
費率取自建置時的即時目錄；各模型頁面皆附有目前的費率卡。
它們的相對位置 — 在此計費單位下，所有 68 個 聊天 模型的 每 1M tokens 的輸入價格（對數尺度）
能力
| GPT-5.6 Terra | GPT-6 Astra | |
|---|---|---|
| 工具使用 | 是 | 是 |
| 思考控制 | 可配置 | 可配置 |
| 結構化輸出 | 是 | 是 |
| 提示快取 | 隱式（自動） | 隱式（自動） |
| 快取生命週期 | 5-10m, up to 1h | 5-10m, up to 1h |
| 最小快取前綴 | 1024 個 token | 1024 個 token |
規格
| GPT-5.6 Terra | GPT-6 Astra | |
|---|---|---|
| 輸入模態 | 文字 影像 | 文字 影像 |
| 輸出模態 | 文字 | 文字 |
| 發布日期 | 2026-07-09 | 2026-09-03 |
| 知識截止日期 | 2026-02 | 2026-04 |
| 上下文視窗 | 1.1M | 1.1M |
| 最大輸出 | 128K | 128K |
| 思考參數 | reasoning.effort | reasoning.effort |
| 可接受的值 | reasoning.effort
| reasoning.effort
|
| 預設值 | medium | medium |
規格摘錄自各供應商的文件；供應商未發布的資料列會直接省略，而非自行推測。 完整來源： GPT-5.6 Terra · GPT-6 Astra
單一提示詞，兩款模型 — 經由閘道測量
GPT-5.6 Terra 通過 · 3 sentences
Enabling reasoning makes the model generate additional internal analysis tokens and perform more computation before producing the final answer, increasing usage per request. Those extra tokens are billed like other model output or are reflected in higher-priced reasoning-model rates, so even unchanged user traffic can cost substantially more. The bill doubled because average cost per request rose, likely from longer reasoning traces, more complex model routing, or both.
輸出 120 tok (+31 思考) 延遲 2.4 s
GPT-6 Astra 通過 · 3 sentences
Enabling reasoning makes the model do more work per request, often generating internal reasoning tokens that are billed even though they do not appear in the final answer. If traffic, model choice, and pricing stayed the same, those extra tokens likely explain why our bill doubled—not longer answers or more users. We should verify the usage breakdown, then reserve higher reasoning levels for tasks where improved results justify the added cost.
輸出 283 tok (+196 思考) 延遲 17.2 s
指令遵循（恰好三句，可數）、受眾適配（面向 CFO 的語氣），以及下方 token 計量所暴露的隱藏思考計費缺口。
GPT-5.6 Terra 通過 · 8/8 cases
```python def longest_run(xs): if not xs: return 0 best = 1 cur = 1 for i in range(1, len(xs)): if xs[i] == xs[i - 1]: cur += 1 else: cur = 1 best = max(best, cur) return best ``` The bug is that `cur` and `best` were counting adjacent *matches* rather than the number of items in a run: a run of one item has zero matching adjacent pairs, and a run of length `n` has only `n - 1` such pairs. Initializing both counters to `1` for a nonempty list and resetting `cur` to `1` when the value changes makes them represent actual run lengths. Updating `best` on every iteration also ensures a run that continues through the final element is included.
輸出 196 tok 延遲 2.6 s
GPT-6 Astra 通過 · 8/8 cases
```python def longest_run(xs): if not xs: return 0 best = cur = 1 for i in range(1, len(xs)): if xs[i] == xs[i - 1]: cur += 1 else: cur = 1 best = max(best, cur) return best ``` The original code counts equal adjacent pairs rather than items, so every nonempty run is undercounted by one: a single-element input returns `0`, and a run of three equal items returns `2`. Starting and resetting `cur` to `1` counts the first item of each run, while the empty-input check preserves a result of `0`. Updating `best` after each iteration includes runs ending at the last index without needing a final flush; the original also updated during trailing runs, but undercounted them.
輸出 321 tok (+131 思考) 延遲 13.5 s
修復是否真的正確（可執行）、解釋的資訊密度，以及在一個邊界明確的任務上的 token 效率。
GPT-5.6 Terra 通過 · 5/5 fields, guidance "withheld pending the Q4 close"
{"company":"Meridian Robotics","quarter":"September quarter","revenue_usd_m":412,"growth_pct":null,"guidance":"withheld pending the Q4 close"}
輸出 149 tok (+103 思考) 延遲 2.3 s
GPT-6 Astra 通過 · 5/5 fields, guidance "Formal guidance is withheld pending the "
{ "company": "Meridian Robotics", "quarter": "September quarter", "revenue_usd_m": null, "growth_pct": "eleven and change", "guidance": "Formal guidance is withheld pending the Q4 close." }
輸出 329 tok (+267 思考) 延遲 16.9 s
schema 服從度（不臆造欄位）、幻覺壓力（guidance 明確被暫緩給出），以及結構化輸出路徑的差異。
GPT-5.6 Terra 通過 · 120 words, 0 banned, 1 question
Today, our API gateway introduces cross-provider prompt caching, reducing repeated token processing while preserving your existing model routing. Teams can store reusable system prompts, policy blocks, and long context prefixes once, then serve them to supported providers with consistent cache keys and observability. The feature tracks hit rates, latency savings, and estimated cost reductions in the dashboard you already use for requests. Why pay to recompute identical context on every call? Configure cache policies by route, tenant, model, or TTL, and fall back automatically when a provider lacks compatible caching. Built-in controls help protect sensitive data through encryption, regional settings, and explicit expiration. Start with a single endpoint, compare results across providers, and scale prompt reuse without rewriting application logic.
輸出 631 tok (+475 思考) 延遲 6.0 s
GPT-6 Astra 通過 · 120 words, 0 banned, 1 question
Introducing Cross Provider Prompt Cache, a new API gateway feature that reuses eligible prompt content across supported AI providers. Why pay to process the same context every time? Configure caching once at the gateway, then route requests between models while keeping shared instructions, reference material, and conversation prefixes ready for reuse. Caching controls let teams set expiration windows, isolate tenants, and exclude sensitive content. Cache analytics show hit rates, estimated savings, and latency trends, helping developers tune performance with confidence. Existing routing policies continue to work, so adoption fits your current architecture. Start with a single application, measure the results, and expand as needed. Available today in the dashboard and API, with documentation and examples to guide your first deployment.
輸出 665 tok (+516 思考) 延遲 19.3 s
約束服從度（字數預算、禁用詞表、唯一的那句問句）、文風指紋，以及長度控制。
只需一行程式碼即可在兩者間切換
以下每個頁籤中都有這兩個 ID — 醒目提示的這兩行是唯一的修改處。相同的端點，相同的金鑰，相同的請求結構。
from openai import OpenAI
client = OpenAI(
base_url="https://synthorai.io/v1",
api_key="sk-syn-...",
)
resp = client.chat.completions.create(
model="gpt-5.6-terra",
# model="gpt-6-astra", # 取消註解此行，並註解上一行
messages=[{"role": "user", "content": "Summarize this diff"}],
reasoning_effort="medium",
)
print(resp.choices[0].message.content)import OpenAI from "openai";
const client = new OpenAI({
baseURL: "https://synthorai.io/v1",
apiKey: "sk-syn-...",
});
const resp = await client.chat.completions.create({
model: "gpt-5.6-terra",
// model: "gpt-6-astra", // 取消註解此行，並註解上一行
messages: [{ role: "user", content: "Summarize this diff" }],
reasoning_effort: "medium",
});
console.log(resp.choices[0].message.content);curl https://synthorai.io/v1/chat/completions \
-H "Authorization: Bearer sk-syn-..." \
-H "Content-Type: application/json" \
-d '{
"model": "gpt-5.6-terra",
# "model": "gpt-6-astra", # 取消註解此行，並註解上一行
"messages": [{"role": "user", "content": "Hello"}],
"reasoning_effort": "medium"
}'package main
import (
"context"
"fmt"
"github.com/openai/openai-go/v3"
"github.com/openai/openai-go/v3/option"
)
func main() {
client := openai.NewClient(
option.WithBaseURL("https://synthorai.io/v1"),
option.WithAPIKey("sk-syn-..."),
)
resp, _ := client.Chat.Completions.New(context.TODO(), openai.ChatCompletionNewParams{
Model: "gpt-5.6-terra",
// Model: "gpt-6-astra", // 取消註解此行，並註解上一行
Messages: []openai.ChatCompletionMessageParamUnion{
openai.UserMessage("Summarize this diff"),
},
ReasoningEffort: openai.ReasoningEffortMedium,
})
fmt.Println(resp.Choices[0].Message.Content)
}import com.openai.client.OpenAIClient;
import com.openai.client.okhttp.OpenAIOkHttpClient;
import com.openai.models.chat.completions.*;
import com.openai.models.ReasoningEffort;
OpenAIClient client = OpenAIOkHttpClient.builder()
.baseUrl("https://synthorai.io/v1")
.apiKey("sk-syn-...")
.build();
ChatCompletion resp = client.chat().completions().create(
ChatCompletionCreateParams.builder()
.model("gpt-5.6-terra")
// .model("gpt-6-astra") // 取消註解此行，並註解上一行
.addUserMessage("Summarize this diff")
.reasoningEffort(ReasoningEffort.MEDIUM)
.build());
System.out.println(resp.choices().get(0).message().content().orElse(""));常見問題
GPT-5.6 Terra 和 GPT-6 Astra 哪個比較便宜？
GPT-5.6 Terra 在 輸入 / 1m tokens 上較便宜（$2.5 對比 $10，相差 4.0×）。其他項目可能呈現相反結果 — 上表提供完整資訊，實際成本取決於您的使用組合。
我可以在不進行兩次整合的情況下，對 GPT-5.6 Terra 和 GPT-6 Astra 進行 A/B 測試嗎？
可以。兩者皆透過同一個相容 OpenAI 的端點提供服務，並使用同一把 API 金鑰 — 切換只需更改一行的模型字串，因此您可以將部分流量分別導向兩者並直接比較帳單。
GPT-5.6 Terra 與 GPT-6 Astra 支援提示快取嗎？
是的 — 兩者的快取讀取費率皆低於其輸入費率，因此具有暖前綴的工作負載成本會低於牌價所示。確切的快取讀取列請見上方的定價表。