how much can be shaved off a big core in a cpu

does a x86 core have to be big to reach 6 ghz 

what can be shaved off a big x86 core 

if 64 x86 cores that reach 3 ghz can fit on a chip, 

but only 16 x86 cores that reach 5.5 ghz fit on a chip, 

what more needs to be removed to enable more cores at a higher ghz

if too much is shaved of cpu cores, will they do less

can all cache be removed from cpu to enable cores that reach a higher ghz