Samsung Galaxy S21 Ultra 5G

CPU RAM:: Exynos 2100

Samsung Exynos 2100 High-End Processor

Details of Eight CPU cores are below

2.9 GHz Cortex X1 Single-core

2.8 GHz Cortex A78 Triple-core

2.2 GHz Cortex A55  Quad-core

These CPU cores work on a dynamic allocation.  e.g.,

1) For gaming that relies on Single-core performance, Cortex XI will be used, which is the most powerful CPU core.

2) For medium-level tasks such as image editing, video editing, etc., Cortex A78 is chosen.

3) For web browsing, Cortex A55 is chosen.

Thus this CPU is one of the most diverse CPUs available as of Early 2021.