How to check capacity gain achieved between 2x2 MIMO vs 4x4 MIMO vs 64x64 through OSS KPIs?

Hi Experts.
Can someone please share how to check capacity gain achieved between 2x2 MIMO vs 4x4 MIMO vs 64x64 through OSS KPIs?

You can compare pre and post before upgrade and after using DL payload.

I am looking some case study observations before going for solution, theory says it provides throughput gain rather capacity for the same amount of users under cells - thp gain is enhanced as you go from 2x2 to 4x4 to 64x64 but capacity (PRB) still remains same?