The Speed of Musk

In late 2024, Elon Musk’s xAI did something the industry thought was impossible. They built a world-class supercomputer, Colossus, in just 122 days. Located in Memphis, Tennessee, this machine isn't just a data center; it is a statement of intent.

As of late 2025, Colossus has doubled in size, now housing 200,000 NVIDIA H100 and H200 GPUs. And they are just getting started. This is the 3,000-word story of how xAI is attempting to out-scale OpenAI and Google using raw engineering speed and massive capital.

---

1. The Memphis Miracle: 122 Days to Power

When xAI announced it was building the "largest AI supercomputer in the world," the traditional vendors told them it would take two years to get the permits, the power, and the fiber optics. Musk’s team did it in four months.

• The Power Challenge: Memphis had to provision 150 Megawatts of power for the site—roughly enough to power 100,000 homes.
• The Cooling: To keep 100,000 H100s from melting, xAI installed a state-of-the-art liquid cooling system, utilizing massive gray-water tanks to avoid straining the city’s drinking water.

---

2. Colossus 2: The 2025 Expansion

By April 2025, Colossus was already being upgraded.

• The GPU Mix: While the original rack used H100s, the 2025 expansion added 100,000 H200s and the first shipments of NVIDIA Blackwell (B200) chips.
• Pre-training Grok 5: In October 2025, xAI officially announced that pre-training for Grok 4 and Grok 5 had commenced on the full 550,000 GPU cluster. This puts xAI’s "compute moat" on par with, or even ahead of, OpenAI’s Project Stargate.

---

3. Grok’s Edge: Real-Time Grounding via X

The secret weapon of xAI isn't just the GPUs; it’s the real-time data from X (formerly Twitter). While GPT-4 and Gemini have to wait for "Scrapers" to find news, Grok is directly connected to the X firehose.

• The Signal: If a major global event happens, Grok knows about it in seconds.
• The Bias Question: Musk has marketed Grok as "anti-woke" and "truth-seeking," intentionally reducing the RLHF-based "Refusals" that plague models from Google and OpenAI. (See our RLHF Guide).

---

4. The Unified Model: Grok x Optimus x FSD

A major 2025 breakthrough for xAI was the integration with Tesla.

• The "Robot Brain": The same foundation models trained on Colossus are being "distilled" to run on the Tesla Optimus Gen 2 and the Full Self-Driving (FSD) computer.
• Physical Reasoning: Because Grok is being trained on video data from Tesla’s millions of cars, it understands the physical world (mass, inertia, gravity) in a way that "text-only" models cannot.

---

5. The $6 Billion War Chest and the Next Round

In 2024, xAI raised $6 billion at a $24 billion valuation. By late 2025, rumors suggest another $10 billion round is in the works, potentially valuing the company at over $60 billion. Musk’s strategy is clear: Compute is the new Gold. If he has the most GPUs and the fastest interconnects, he believes the "Intelligence" will naturally follow.

---

6. The Environmental and Local Controversy

Building a massive supercomputer in the middle of a city hasn't been without friction.

• Noise Pollution: The cooling fans at Colossus are so loud they can be heard for miles.
• Ethical Concerns: Critics argue that burning enough electricity to power a small city just to train a chatbot is "ecologically irresponsible." xAI has countered by investing in massive Tesla Powerwall arrays and solar farms to offset the load.

---

Conclusion

xAI is the "Wild Card" of the AI wars. While OpenAI is the "Academics" and Google is the "Institution," xAI is the "Disruptor."

With Colossus, Musk has proven that if you have enough money and a high enough risk tolerance, you can bypass the traditional gatekeepers of technology. As we look toward the launch of Grok 3 in late 2025, the question is: Can raw compute beat years of research? In the age of scaling, the answer might just be "Yes." The battle for 2026 is no longer about who has the best algorithm; it’s about who has the biggest cluster. And right now, the biggest cluster is in Tennessee.