Two scenarios:- * When upstream supports higher aggregate QPS than what Nginx can support on a host, nginx has better CPU performance than HAProxy. (Nginx == 700% CPU, HAProxy = 1200% CPU) * When upstream capacity is limited, and my benchmarking tool sends QPS higher than what the upstream supports, nginx is showing unbelievably high CPU usage when compared to HAProxy. (Nginx == 400% CPU, Hby shadyabhi - Nginx Mailing List - English