3 ms·

"Adding more cores to a CPU did help mitigate this and we tested some of the high core count AMD CPUs, but ultimately decided against going that direction." Yo

• rtkwe 13y ago
  > While top clockspeed was not our priority, our product roadmap includes more CPU-heavy features. These include image optimization (e.g., Mirage and Polish), high volumes of SSL/TLS connections, and extremely fast pattern expression matching (e.g., PCRE tests for our WAF). These CPU-heavy operations can, in most cases, take advantage of special vector processing instruction sets on post-Westmere Intel chips. This made Intel's newest generation Sandybridge chipset attractive. and > We were willing to sacrifice a bit of clockspeed and spend a bit more on chips to save power. We tend to put our equipment in data centers that have high network density. These facilities, however, are usually older and don't always have the highest power capacity. We settled on our G4 servers having two Intel Xeon 2630L CPUs (a low power chip in the Sandybridge family) running at 2.0GHz. This gives us 12 physical cores (and 24 virtual cores with hyperthreading) per server. The power savings per chip (60 watts vs. 95 watts) is sufficient to allow us at least one more server per rack than we'd be able to get if we went with the non-low power version. So a combination of additional instructions and power savings.