Studio Display and Studio Display XDR have A19 and A19 Pro chips inside.

Joe Rossignol from MacRumors:

Apple's press release and marketing materials for the new Studio Display and Studio Display XDR models do not mention which chips are inside the monitors, but MacRumors has confirmed this information in the latest Studio Display firmware.

The firmware reveals that the second-generation Studio Display is equipped with an A19 chip, while the Studio Display XDR has an A19 Pro chip, according to code reviewed by MacRumors contributor Aaron Perris. Rumors had mentioned either the A19 chip or the A19 Pro chip, and it turns out that the two chips are split across the two models.

I was about to write about this exact topic, wondering why Apple didn’t reveal the chipset in these two devices. In 2022 they did discuss the A13 chip and how it was responsible for the Center Stage camera, “Hey Siri” support, and Spatial Audio among other functions. No doubt the A19 Pro is pulling a lot of muscle with all the new features, including medical grade imaging in the XDR model.