Another thought: If the same browser shared library can be used for every process, the same RAM pages should be executed for each process, so the CPU should be

Another thought: If the same browser shared library can be used for every process, the same RAM pages should be executed for each process, so the CPU should be able to keep more of the code in CPU cache, along with probably branch prediction statistics as well. To the CPU it is the same code running which has many performance impacts. Less code = faster.