Looking at both 64 and 56 pcb i am under the impression that there both the same ref design vrm's components ect so cost wise i would suspect its the same cost to make ....now either the 56 is a cut down 64 either from partial faulty die or just cut down from 64 and locked via bios ect
so either way they cost the same ...that's what i see ...
yeah but its about yields for a big part, if e.g. 20% of the fabric is useable for 64s but 50% is useable for 56s then the 56s are much cheaper to produce.