Check this out:
Single core performance can sometimes be more valuable than more cores, as all processing on a channel or individual plugins could be limited to one core. This has historically been the case with a lot of DAW:s and plugins.
I run an 8700K myself which has a significantly higher clock speed then the I9 18 core. I havn´t tested but I suspect it would beat an I9 under certain Cubase loads, and certainly for most current games and desktop programs etc. That said, the I9 would crush the competition in a multi-threaded environment. Not sure how well Cubase scales with more than 12 logical cores, anyone?