Which GPU does OpenAI use?

I've been following the advancements in artificial intelligence, particularly the groundbreaking work done by OpenAI. However, one question that has been lingering in my mind is: What GPU does OpenAI actually utilize to power their state-of-the-art models? With the rapidly evolving landscape of graphics processing units, it's fascinating to know which hardware enables such cutting-edge research. Is it a specific brand or model that provides the necessary computational prowess? Or perhaps OpenAI has developed a custom solution tailored specifically for their needs? I'm eager to understand the technological backbone that drives this revolutionary organization.