Per-thread performance is around 1/4 - 1/3 of a Xeon E5: https://www.anandtech.com/show/10353/investigating-cavium-thunderx-48-arm-cores/12 https://www.anandtec

Per-thread performance is around 1/4 - 1/3 of a Xeon E5: https://www.anandtech.com/show/10353/investigating-cavium-thunderx-48-arm-cores/12 https://www.anandtech.com/show/10353/investigating-cavium-th... With enough parallelism they outperform Xeons on some tasks, but not on others: https://www.anandtech.com/show/10353/investigating-cavium-thunderx-48-arm-cores/13 https://www.anandtech.com/show/10353/investigating-cavium-th... You'd have to benchmark for your particular application, which is only worth doing if you'd be buying 10s of servers.