AI HOT (Curated Pool)Jun 28, 2026, 18:50 UTC+8

Grok 4.5 enters private testing at SpaceX and Tesla, performance near Opus

Grok 4.5 私测于 SpaceX 和 Tesla，性能接近 Opus

Elon Musk says Grok 4.5 is built on a 1.5T-parameter V9 base model with Cursor data added during supplementary training, now in private testing at SpaceX and Tesla. Early evals show performance close to or possibly exceeding Opus. RL is still improving the model, and the Grok Build toolchain is maturing. SpaceX will also release a fully from-scratch trained model every month this year. The post doesn't specify which Opus model, benchmarks, or testing scale.

Why it matters: Musk's own tease of Grok 4.5 vs Opus with Cursor data injection is strong signal. But no benchmark names, Opus version, or sample size disclosed — caps at 78.

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The reason to click: 1.5T parameters, Cursor data in training, and private testing inside SpaceX and Tesla — that's a real signal. But Musk only says early evals are "close to or possibly exceeding Opus" without naming which Opus version, which benchmarks, or how many samples. I'd discount that a bit. xAI's eval claims tend to run optimistic, and "close to Opus" is too vague to compare against Claude Sonnet 4.5 or GPT-5 directly. Two things actually worth tracking: how Cursor data was incorporated — if it includes code-editing trajectories, that could directly help coding agents — and SpaceX shipping a fully from-scratch model every month. That cadence is faster than most labs. What's missing: third-party benchmarks and an API timeline. Don't read this as open-weight catching closed-source yet.

Source: AI HOT (Curated Pool) · x.com
Published: Jun 28, 2026, 18:50 UTC+8 · Jun 28, 2026