OpenAI has begun rolling out its newest AI model, GPT-4.5, to users on its ChatGPT Plus tier, marking a significant milestone in the company's artificial intelligence development. The rollout, which is expected to take 1-3 days, comes on the heels of the model's initial launch for subscribers to OpenAI's $200-a-month ChatGPT Pro plan last week.

GPT-4.5 is OpenAI's largest AI model yet, trained using more computing power and data than any of the company's previous releases. While its size and capabilities are impressive, GPT-4.5 falls short of newer AI "reasoning" models from Chinese AI company DeepSeek, Anthropic, and OpenAI itself on several AI benchmarks.

One of the most notable aspects of GPT-4.5 is its high cost. OpenAI admits that running the model is extremely expensive, which has led the company to evaluate whether to continue serving GPT-4.5 in its API in the long term. As a result, GPT-4.5 is OpenAI's priciest model in its API, with a cost of $75 per million tokens (~750,000 words) fed into the model and $150 per million tokens generated by the model. This is 30 times the input cost and 15 times the output cost of OpenAI's workhorse GPT-4o model.

Despite its high cost, OpenAI claims that GPT-4.5's increased size has given it "a deeper world knowledge" and "higher emotional intelligence." The model also hallucinates less frequently than most models, according to OpenAI, which in theory means it should be less likely to make stuff up. Additionally, GPT-4.5 is very persuasive, with one of OpenAI's internal benchmarks finding that the model is particularly good at convincing another AI to give it cash.

The rollout of GPT-4.5 raises important questions about the future of AI development and deployment. As AI models continue to grow in size and complexity, the cost of running them will likely increase, leading to a potential bottleneck in adoption. Furthermore, the high cost of GPT-4.5 may limit its accessibility to only those with the means to afford it, potentially exacerbating existing inequalities in the AI landscape.

Despite these challenges, the release of GPT-4.5 marks an important step forward in AI research and development. As the technology continues to evolve, it will be important to monitor its implications and potential applications, as well as the efforts of companies like OpenAI to make AI more accessible and affordable for all.