So-called reasoning AI models are becoming easier and cheaper to develop. On Friday, NovaSky, a team of researchers based out of UC Berkeleys Sky Computing Lab, released Sky-T1-32B-Preview, a reasoning model thats competitive with an earlier version of OpenAIs o1 on a number of key benchmarks. Sky-T1 appears to be the first truly open source reasoning model in the sense that it can be replicated from scratch; the team released the data set they used to train it as well as the necessary training code.Remarkably, Sky-T1-32B-Preview was trained for less than $450, the team wrote in a blog post, demonstrating that it is possible to replicate high-level reasoning capabilities affordably and efficiently.$450 might not sound that affordable. But it wasnt long ago that the price tag for training a model with comparable performance often ranged in the millions of dollars. Unlike most AI, reasoning models effectively fact-check themselves, whichhelps them to avoid some of thepitfallsthat normally trip up models. Reasoning models take a little longer usually seconds to minutes longer to arrive at solutions compared to a typical non-reasoning model. The upside is, they tend to be more reliable in domains such as physics, science, and mathematics.The NovaSky team says it used another reasoning model, Alibabas QwQ-32B-Preview, to generate the initial training data for Sky-T1, then curated the data mixture and leveraged OpenAIs GPT-4o-mini to refactor the data into a more workable format. Training the 32-billion-parameter Sky-T1 took about 19 hours using a rack of 8 Nvidia H100 GPUs. (Parameters roughly correspond to a models problem-solving skills.)According to the NovaSky team, Sky-T1 performs better than an early preview version of o1 on MATH500, a collection of competition-level math challenges. The model also beats the preview of o1 on a set of difficult problems from LiveCodeBench, a coding evaluation. However, Sky-T1 falls short of the o1 preview on GPQA-Diamond, which contains physics, biology, and chemistry-related questions a PhD graduate would be expected to know.Also important to note is that OpenAIs GA release of o1 is a stronger model than the preview version of o1, and that OpenAI is expected to release an even better-performing reasoning model, o3, in the weeks ahead.But the NovaSky team says that Sky-T1 only marks the start of their journey to develop open source models with advanced reasoning capabilities. Moving forward, we will focus on developing more efficient models that maintain strong reasoning performance and exploring advanced techniques that further enhance the models efficiency and accuracy at test time, the team wrote in the post. Stay tuned as we make progress on these exciting initiatives.