Launched shortly after GPT-4's debut in March 2023, the project—codenamed Orion—faces delays, mounting costs, and doubts about its feasibility. 

Microsoft, OpenAI's largest investor, had anticipated a mid-2024 release for GPT-5. However, insiders reveal that at least two major training runs have failed to deliver the desired results, with researchers encountering unforeseen issues each time.

These training efforts, which reportedly cost around half a billion dollars each, have yet to produce the "significant leap forward" promised by OpenAI CEO Sam Altman. 

A core issue for Orion is data scarcity. OpenAI's researchers concluded that the public internet no longer provides the high-quality, diverse datasets needed for the model's development. To address this, the company has turned to generating synthetic data, hiring software engineers, mathematicians, and theoretical physicists to create original content. 

These experts write software code, solve mathematical problems, and provide detailed explanations of their reasoning, offering Orion a deeper understanding of complex topics. But the process is labor-intensive and slow.

While GPT-4 was trained on approximately 13 trillion tokens, a team of 1,000 people producing 5,000 words daily would take months to generate just a billion tokens. 

This scarcity of usable data has sparked broader industry concerns. Ilya Sutskever, OpenAI's co-founder and former Chief Scientist, recently described data as "the fossil fuel of AI" at an AI conference, warning that "we have but one internet" and suggesting that data growth has plateaued. 

OpenAI's struggles extend beyond technical hurdles. The company has faced a wave of departures among key executives and researchers, including Sutskever and Chief Technology Officer Mira Murati.

Alec Radford, a prominent researcher and lead author of several foundational OpenAI papers, announced his resignation after nearly eight years at the company. 

This exodus has left OpenAI vulnerable to rivals, many of whom are actively headhunting its top talent with multimillion-dollar offers. The loss of institutional knowledge has compounded the challenges facing the GPT-5 project. 

The stakes for OpenAI are enormous. The company's $157 billion valuation hinges largely on the promise of GPT-5, which Altman has touted as a transformative leap in AI capabilities. Yet insiders describe the project as lagging far behind expectations. 

Researchers at OpenAI reportedly rely on subjective "vibes" to assess whether Orion is ready to be designated as GPT-5. So far, the results have not been encouraging.