I must be confused, my understanding was m7a was 4th generation Epyc (Genoa, Bergamo and Siena) which I believe all have 2 threads per core no?
> One of the major differences between M7a instances and the previous generations of instances, such as M6a instances, is their vCPU to physical processor core mapping. Every vCPU on a M7a instance is a physical CPU core. This means there is no Simultaneous Multi-Threading (SMT). By contrast, every vCPU on prior generations such as M6a instances is a thread of a CPU core.
My wild guess is they're disabling it. For Intel instance families they loudly praise their custom Intel processors, but this page does not contain the word "custom" anywhere.