There is a more interesting dimension to that question. ARM chips tend to come with more third party accelerators. And I think there are more silicon vendors

There is a more interesting dimension to that question. ARM chips tend to come with more third party accelerators. And I think there are more silicon vendors that are willing to cram more cores on to a chip. In the server space I'd think that it will be Intel with furious single core performance and maybe 10 or 20 cores total vs ARM based with 32-64+cores and some hardware acceleration for some more operations. It will some how be an asymmetric comparison unless someone starts really knocking out high performance ARM cores.