Judging the 18-core iMac Pro →

Craig Hunter has put the 18-core iMac Pro through its paces:

So in summary, we see performance increases ranging from 27% to 79% for the 18-core iMac Pro when compared to the 10-core model. I suspect many computations and applictions will be in the middle of that range depending on how well they can take advantage of multiple cores, but there will certainly be some hot rod uses that get closer to that 79% end of the scale (and may do even better). Though I haven’t mentioned it, if you look back through the various benchmark results, you’ll see that the 18-core iMac Pro shows no disadvantage for single-core performance, despite running at a lower clock speed (2.3GHz/4.3GHz) than the 10-core iMac Pro (3.0GHz/4.5GHz).

I figured the higher core count would come at a higher cost in terms of single-core tasks.

Hunter concludes that the 18-core machine, while expensive, is worth the upgrade over the 10-core if you’ve got the cash.