`pevm` is not working well on AMD?

Isolated Ethereum benchmarks (Gigagas is fine) run poorly on an AMD bare metal. It may suggest that threads on this bare metal are currently very expensive. We may need to look into hyperthreading or whatever to ensure `pevm` excels on this machine.

The suspect on AMD is because `pevm` doesn't face this issue on Intel or ARM (my Desktop and several AWS instances).
