GPT-5.6 Terra Max vs Grok 4.7 Xhigh: speed, latency and cost

This comparison puts OpenAI's GPT-5.6 Terra (Max) next to SpaceXAI's Grok 4.7 (Xhigh). Once text starts flowing, GPT-5.6 Terra Max is the quicker writer by a wide margin, at 1.8 times the output speed of Grok 4.7 Xhigh. What follows is built entirely from tracked data, so where the catalogue is silent, this page says so instead of guessing.

GPT-5.6 Terra Max is the faster writer

Measured output speed is 116 tokens per second for GPT-5.6 Terra Max and 65 tokens per second for Grok 4.7 Xhigh. GPT-5.6 Terra Max is ahead by 78% on throughput. The wait for the first token averages 3.4 minutes on GPT-5.6 Terra Max against 43 seconds on Grok 4.7 Xhigh. The faster writer, GPT-5.6 Terra Max, gives away too much at the start to win on time: counting the first-token wait, Grok 4.7 Xhigh finishes first for any reply shorter than about 24,000 tokens. A first-token wait of that length suits background work better than live conversation.

Put together, a 1,500-token answer would take about 3.6 minutes from GPT-5.6 Terra Max and 66 seconds from Grok 4.7 Xhigh, counting the first-token wait.

Reasoning and overall scores

GPT-5.6 Terra Max records 32.3 on the intelligence index and Grok 4.7 Xhigh records 35.5. A lead of this size is hard to dismiss as noise. In relative terms, Grok 4.7 Xhigh scores 10% higher.

Among 109 active scored models, GPT-5.6 Terra Max sits 46th and Grok 4.7 Xhigh 38th.

Specialist coding and math indexes are missing for both, so treat the overall score as the only capability signal here.

When they came out

GPT-5.6 Terra Max came first, on July 9, 2026; Grok 4.7 Xhigh followed on September 21, 2026.

Price per token

The list prices are $2.00 in and $12.00 out for GPT-5.6 Terra Max, and $2.00 in and $6.00 out for Grok 4.7 Xhigh, per million tokens. For output tokens, GPT-5.6 Terra Max is twice the price of Grok 4.7 Xhigh.

A reference job of 1 million input tokens and 200,000 output tokens costs $4.40 with GPT-5.6 Terra Max and $3.20 with Grok 4.7 Xhigh, so Grok 4.7 Xhigh saves $1.20. For a chat app with 50,000 sessions of 800 input and 300 output tokens, Grok 4.7 Xhigh would come in 35% lower: $260 for GPT-5.6 Terra Max against $170 for Grok 4.7 Xhigh.

Is the price in proportion?

A blunt value measure, blended price over intelligence score, puts GPT-5.6 Terra Max at $0.14 and Grok 4.7 Xhigh at $0.085 per point. Grok 4.7 Xhigh scores higher and costs less per point, so on price per point there is nothing to trade off.