There are not so many differences, but they are
Redmi K30 Ultra is a new model: sales started in China only, so the smartphone hasn’t been lit up in a full-fledged disassembly. However, images of the official comparison of the K30 Ultra and the K30 Pro give some idea of what the model looks like from the inside.

There are not so many differences, but they are noticeable. For example, the K30 Ultra has a different screen – an AMOLED E3 panel with a frame rate of 120 Hz. On the reverse side, you can see that the new product also uses a different fingerprint scanner and the layout of the control electronics has changed.

The same can be said about the motherboard – along with the change in the layout, its dimensions have also slightly decreased.

In the Redmi K30 Ultra, a linear motor acts as an auditory loudspeaker, which is also responsible for vibration. The source calls this a 2-in-1 solution. At the same time, its dimensions have decreased by about half.
Source: ITHome