News AMD Epyc Expands Inside Google Cloud

Considering you can get up to 224 vCPUs they have to be 64 core variants. Then from Google's documentation you see "N2D machine types run on AMD EPYC Rome processors with a base frequency of 2.25 GHz, an all-core turbo frequency of 2.7 GHz, and a single-core turbo frequency of 3.3 GHz. " The only CPU that meets those requirements with 64 cores are the 7742s.
 

bit_user

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Considering you can get up to 224 vCPUs they have to be 64 core variants. ... The only CPU that meets those requirements with 64 cores are the 7742s.
Customers as big as Google can get customized versions of AMD's product stack, like they did with the Vega GPUs they're using in Stadia. Intel also offers custom variants for big customers.

To get 224 vCPUs, you only need 2x56 cores x2 threads. So, maybe they're using 7-chiplet variants or the slowest core on each of the 8 chiplets has been disabled. Or, they could be reserved for some kind of management functions.