The speed of reading information in UFS 3.1 storage memories is up to 2100 MB/s and the speed of writing information on them is up to 1200 MB/s. On the other hand, the speed of reading and writing information in UFS 4.0 chips can reach 4200 and 2800 megabits per second, respectively.
According to what was said, the speed of UFS 4.0 memory is at least twice that of UFS 3.1. Thus, technically, the 128 GB version of the Galaxy S23 will be slower in opening applications, booting the operating system and running games than its 256 GB model. Therefore, it seems more logical to choose the 256 GB version of this phone.